A juvenile fantasy novel with the hero being tutored by two famous Jacks from fairy tales

Question

I'm looking for a juvenile fantasy novel, written in English, with at least a few interior illustrations, which I borrowed from a library sometime in the early-to-mid 1980s. I found it very entertaining at the time, and I'd like to check up on it and see if I still like it today. The problem is that I remember precious little about the details of the plot.

Here's the bits and pieces that I do recall:

1. It was set in a medieval fantasy world where some of the famous fairy tales of the Western world were matters of historical fact.

2. It was aimed at a juvenile audience. (I was maybe 10 at the time I first read it, and I suspect that "kids around 10 or 12, and still fond of fairy tales" were the intended target audience.)

3. The most distinctive thing that I recall about the plot is this: The boy who is the main character becomes acquainted with two legendary heroes: "Jack and Jack." More specifically, one of these men is the title character from "Jack and the Beanstalk," and the other guy is "Jack the Giant-Slayer," who fought and killed seven giants (each in a separate encounter) in another classic fairy tale. But several decades have rolled past since those events, and now the Jacks are old men. They live quietly in a cave (or some other remote location), and they still have some of the special equipment acquired in their younger days (such as magic items taken from their defeated foes). I believe at least one or two such items are handed over to the young hero to get him off to a good start.

4. This is important because the young hero (an original character) has just learned that he is supposed to go on a Very Important Quest. I don't recall how he got stuck with the job in the first place, nor am I clear on what the quest was all about! Possibly he was meant to find and kill a troublemaking giant as part of the mission -- but that's sheer speculation on my part, based largely on my recollection that these two veteran giant-killers are supposed to help him prepare for it (instead of, say, stars of other fairy tales who had fought other types of foes).

5. I'm sure the tale had a happy ending, but I don't remember a thing about what the hero actually did to gain a "victory." Nor what sort of rewards he received for his trouble! I hope he received something, though. (I have the distinct impression that he was just your typical commoner when this started, probably from a peasant family -- definitely not raised as a prince, nor as any type of nobility.)

Answer 1

Could it be: Are All the Giants Dead? by Mary Norton, illustrated by Brian Froud

James, a young English boy, journeys to the fairy-tale world of princes and princesses, witches and fairies, giants and giant-killers, and invades the lair of the last giant to free a princess from an evil spell.

From Collected Miscellany:

One night, when he should be safe in bed, young James is whisked away by his friend Mildred to the fairy tale land of Happily Ever After. There Cinderella and Sleeping Beauty are middle-aged gossips; Bell’s husband, the Beast, spends his days hunting dragon and unicorn; And Jack-the-Giant-Killer and Jack-of-the-beanstalk while away their retirement telling yarns about slaying the last of the giants.

But the two Jack’s aren’t quite telling the truth: one fierce man-eating giant still lives. And to spare his friend Princess Dulcibel from having to marry an enchanted toad, James must steal something from the dreaded giant’s bone-strewn lair, a place where even the veteran giant-killers fear to tread.

A snippet from the British Book News on Google Books shows this image when searching for Jack Giant killer:

Young James is transported by magic into an ageing fairytale world. He joins Jack the Giantkiller and Jack of Beanstalk fame in their quest for the last giant left alive.

It was originally published in 1975 and reprinted in 1997.

A review can be found on tor.com: A Look at Something Larger: Are All the Giants Dead?

Going off information from the tor.com link:

1. James travels to a world where famous fairy tales of the Western world were matters of historical fact, and famous fairy tale characters are real people.

2. James is around the ages of 10 to 12.

3. James and Mildred find Jack the Giant Killer and Jack of the Beanstalk, now old men running an inn

4. James has to find a certain frog—and just possibly face a giant, a witch, and some hobgoblins to save a Princess

Answer 2

Is it "The Last of the Giant Killers: Or, The Exploits of Sir Jack of Danby Dale" By John Christopher Atkinson? This is the picture I found of the cover.