Child's science fiction book about kids in space with a metal disk and an alien chasing them after it

Question

I recall reading a book in the 5th grade about a boy, a girl and a dog that end up traveling through space with an odd lizard-like alien. The kids found a piece of metal (a disk) and nailed it to their play "space ship" they have built. The alien is sort a master of disguise but he does it rather poorly. And he is out to recover the metal disc.

This weird metal gives the little club house/space ship the ability to fly and go into out into the solar system to visit some of the planets. I recall they go to Venus and almost get devoured by some type of creature. Oddly, the kids and dog have to wear clothespins on their noses to keep from perishing in space as the result of some drug the alien has given them. It is an odd plot for sure, but it was a cool book for a kid.

Answer 1

This sounds very much like Rusty's Space Ship By Evelyn Shipley Lampman, 1957.

Two children, Rusty and Susan, build a play spaceship, which becomes a real spaceship when they get involved with a lizard like alien who visited Earth and now wants to return to his home planet Eopee.

It is mentioned in various previous answers:

• Kids' book about boys finding a disc from a planet called "Eyopee"

• 60's book about a boy who builds a spaceship from cardboard in garage

• Children's novel: three children (plus dog?) travel to the Moon in pretend spaceship turned real

My answer to this question about navigation in space wonders whether the alien in Rusty's Space Ship ever found his home:

https://worldbuilding.stackexchange.com/questions/180161/finding-earth-on-a-star-map/180214#180214[1]

Answer 2

As per Children's book with a small green alien who has a metal umbrella as a spaceship, this may be Rusty's Spaceship by Evelyn Lampman.

Rusty bad built the Terra Terror I out of a box and some tin cans, and it was hardly the kind of space ship for a trip to the moon! But, nevertheless, Rusty and Susan found themselves flying through space with a messenger from Eopee and a flying saucer attached to their ship.