I am not really scraping the bottom of the barrel as much as taking the time to post the most obscure stuff in my space book collection. I collected almost any pre 1980 children's book about spaceflight. I preferred the non-fiction but picked up some strange fiction and comics along the way. (Giant carrots from the Moon anyone?)
So Mournful Mouse and The Space Trip is part of a series of books. This was the only one about rockets or space. It was the author's self-published effort. The two sizes of type on each page are odd. It seems (to our modern eyes) THAT THE OTHER VOICE IS YELLING.
A simple story: a mouse boy finds a sky rocket, accidently gets launched to the Moon, and makes it home for the picnic (with a stomach-ache.)
I do not understand the Mournful Mouse character either.
Schmock, Helen H. Illustrated by Schmock, Helen H. Mournful and The Space Trip. (The Adventures of Mournful Mouse, Book 3.) Ludington, MI: J & H Publishing. (16 p.) 1963.