Yes, several abridged versions have been made available;
The (2009) Highbridge Radio Edit (full cast)
The (2002) BBC Radio Edit (full cast)
The (1993) Martin Shaw Abridged Audiobook
The (1986) BBC Radio Edit (full cast)
The (1979) Jackanory Radio Edit
The (1964) Princess Magazine Serialisation ( http://www.tolkienlibrary.com/tolkien-book-store/PC000007.htm)
This is "Peter Graves" by William Pene du Bois. The anti-gravity material is called Furloy.
It's a short book though, not a short story. Published in 1950. My copy is from 1972.
The cover image shows the harness you mention (with golf club head covers holding the Furloy balls, and a fishing rod safety tether).
And here's a scan of an interior illustration ...
If you're looking for a picture book, there's a 1999 graphic novel you could look for. Otherwise there are a various illustrated editions that might be appropriate for reading along with; I found a list that includes several of them.
Apparently there's even been a pop-up book, though it's not the complete story.
Bugs Bunny's Carrot Machine (1971)
Here is a picture of the machine and Bugs putting junk in to get it to work.
And the machine does eventually break down explode due to Bugs being too greedy and shoving too much junk into it as shown above.
The whole thing is being shown in this YouTube video:
Could this be Rusty's Space Ship (1957) by Evelyn Sibley Lampman?
There was no way for Rusty Adams to know that the shiny metal disc he had found at the city dump and used on his play space ship in the garage, was actually the flying saucer of the Mighty Gwump of Eopee in Adromeda Galaxy. When tiny Tiphia, Gwump's messenger, arrived to claim it, Rusty and ...
I'm pretty sure you're thinking of The Faraway Tree, a series by English author Enid Blyton. Books in the series include The Enchanted Wood and The Magic Faraway Tree.
The "pancake person" was probably Moon-Face, named for his round face that looks like the moon.
In the first novel in the series, Jo, Fanny and Bessie move to live near a large wood. One ...
This sounds a bit like The Hounds of the Morrigan by Pat O'Shea. There is a Wikipedia article on the book here. This was published in 1985 so it fits your time frame, but it's a lot longer than 60,000 words.
The bit I remembered was the handcuffs, but they were made from daisy chains not dandelions. Brigit puts the handcuffs on the witches Melodie Moonlight ...
Bob Fulton's Amazing Soda-Pop Stretcher: An International Spy Story (1963) by Jerome Beatty Jr.
Child prodigy Bob Fulton invents a machine that will turn one bottle of soda pop into several. Something goes wrong and the machine explodes. That's when he discovers it turned the soda into the perfect frictionless lubricant. His sister and her friends use it to ...
The series is the "My Robot Buddy" series by Alfred Slote. The books in the series include:
My Robot Buddy (1975)
My trip to Alpha I (1978)
C.O.L.A.R. : a tale of outer space (1981)
Omega Station (1983)
The Trouble on Janus (1985)
The androids looked exactly like humans, except that they could only walk without bending their knees.
This was a ...
Great job including enough information to find the book! Using ISFDB, I believe I've found it: The Book of Dragons, edited by Michael Hague. It includes "The Adventures of Eustace" by C.S. Lewis and "The Dragon Tamers" by E. Nesbit. There was also an excerpt from The Hobbit. It also includes interior artwork by Michael Hague.
The cover art is:
The full ...
This is probably P. L. Travers's book series about the magical nanny Mary Poppins, of which the first two books are Mary Poppins (1934) and Mary Poppins Comes Back (1935).
Mary Poppins is the babysitter to the Banks family. She takes care of Jane and Michael (who are probably just below school age), John and Barbara (who turn one year old at the end of ...
The Lost Kingdom of Karnica by Richard Kennedy. Illustrated by Uri Shulevitz.
There is a Kirkus review of the book here. The summary they give is:
A parable of greed, a conservationist allegory, but also a forceful, beautifully told story.
In the Kingdom of Karnica, an enormous red gemstone is found at the bottom of a well; and life, "not especially ...
Sounds like Earthdark, by Monica Hughes.
It is set on the moon. Kepler Masterman found life difficult on his return from an exciting trip to Earth. Seeking excitement he took a forbidden trip to the Moon's surface, which nearly cost him his life. On returning to he found his girlfriend's father had disappeared. Danger everywhere and in the unknown region ...
Encounter Near Venus by Leonard Wibberley (1967)
From the Kirkus review:
Four children (two brothers -- two sisters) are sent to their
mysterious Uncle Bill's house in a Colorado wasteland for an eight
week summer vacation. Before their plane lands they have managed to
spot two flying saucers (one pink). Equally colorful adventures are in
Short answer: This is The Voyage of the Luna 1 (1948) by David Cragie.
I asked a question about this book at the Reddit Tip Of My Tongue site about a month ago.
Someone with the user name ceefrock answered that it might be The Voyage of the ...
Dark Life (2010) by Kat Falls?
From Scholastic, which lists it at aimed for 10-13 years old:
Dark Life is set in an apocalyptic future where rising oceans have swallowed up entire regions, the Earth's shifting plates have fractured entire continents, and pollution has eaten away the ozone layer. On the dry land left, people live packed like sardines, ...
This is Others See Us by William Sleator as covered in this answer.
Just before a gathering of relatives, Jared, 16, falls into a swamp polluted with toxic waste; soon after, he discovers that he can read minds, learning--to his horror--that outwardly perfect cousin Annelise is a monster who's already responsible for the death of one fancied rival and the ...
This is an old French fable usually called "Peter and the Magic Thread", "Peter and the Golden Thread" or just "The Magic Thread" and has been retold many times.
You may have read it in William J Bennett's A Book of Virtues, which is a compilation of moral fables and other cautionary tales. This link shows the story of Peter and the thread:
This sounds like Akiko books. The first book is Akiko on the Planet Smoo.
Fourth grader Akiko finds a spacecraft hovering outside her window one night, is whisked off to planet Smoo to find kidnapped Prince. How can Akiko head a rescue mission when she's afraid to be on the school's safety patrol? The team includes -- Spuckler Boach, Gax, Poog, and Mr. ...
According to some fragments I found in New Statesman, vol. 46 it could be
The Man from Outer Space by Douglas V. Duff (1953).
There is certainly a being (The Ancient) from some miles off in The
Man front Outer Space but he remains sadly earth-bound. He is planning
world conquest from a new-fangled submarine and can assume any human
Could this be A Billion for Boris by Mary Rodgers?
When Ape Face fixes a broken-down television set Boris sold to him, something unusual happens. Instead of regularly scheduled programs, this TV shows the future -- one day in advance! They get tomorrow's shows, tomorrow's movies, and tomorrow's news. Annabel thinks they should use their new TV with ESP to ...
The book is Phillip the Flower-Eating Phoenix, by John Todaro and B. Ellen, published by Abelard Schuman in 1961. The colorful illustrations seem to be made of paper cutouts like those Matisse used. I found it by Googling for "flower-eating bird" kirkus, which gained me a brief Kirkus review published September 15, 1961. Armed with the title and name of ...
Going out on a limb here, but The Snowstorm by Beryl Netherclift?
Farthingales is Aunt Amethyst. The children agreed on that. She was
trying valiantly to save the gabled old house in the English
countryside, which was beset by taxes and falling into ruin. From the
first day of their visit, Caroline, Richard, and Kit were determined
Singer to the Sea God by Vivien Alcock
A grand adventure set in ancient Greece. One look at Medusa, and Cleo
turns to stone. Phaidon cannot leave Cleo behind when he escapes with
his uncle and two other slaves. But the sea trader who has helped them
now abandons them, taking Cleo with him. Marooned on an island haunted
by strange echoes, they face ...
As noted by Brian above, this could be the Beast Quest series ghostwritten under the name of Adam Blade. A general overview of the series:
If you, like I, were worried that Adam Blade's Beast Quest would be an extremely black-and-white adventure series about children pointlessly slaughtering Always Chaotic Evil "monsters", you can stop worrying. It's not ...
While it doesn't have "Chronicles" in the title, The Circle of Magic series by Debra Doyle and James D. Macdonald fits plotwise. In the first book, School of Wizardry, we encounter Randal, a squire in his Uncle's household, training to eventually become a knight, who instead goes with the wizard Madoc to learn magic at a school which, yes, is in a castle. ...
Under the heading of possible conflation of sources, Scholastic Press put out The Secret Kingdom in 2011, first book of Chronicles of the Red King, which is about the ancestor of Charlie Bone, who was sent to a magic school in his first book, Midnight for Charlie Bone.
It could be Where do the Wicked Witches Live? by Juliet Snape and Charles Snape.
The Books for Keeps review is:
Dennis sets out to discover where witches live. As he searches over
the hills and beyond the trees, he doesn't know that wicked witches,
sleek cats and all manner of creepy creatures are observing him all
the way! Cleverly concealed in ...