You don't mention the size.
It looks much like a "Junior Elf Book" without the glossy (acetate) surface on the boards--they are roughly 4" x 5" .
Of course it could be much larger--nothing to scale against--or smaller. German children's books from Rand McNally strike me as an oddity but not surprising. I've not seen one and I look at all of these I see: odd, but there was a large diaspora of German speaking people, a lot of them Jews in this period. My mother's people immigrated at that time. I also happen to live near a large community of Amish--Pennsylvania Dutch, really German primitive Christians--so there are a lot of German language books around.
So... McNally has a few ways of determining true age and copyright isn't one of them. At first they would number by the thousands (first thousand, 12th thousand), then by impression. Children's books would get a similar treatment but it would be like Copyright 1932, 1944 edition or something along those lines.
The Junior Elf's have a code--4315 or something like that. Sometimes with a hyphen. The latter 2 digits are MSRP, in cents, the first digits are the year of publication. When the first two digits match the copyright year last two, it's a good chance it is a first edition.
Of course the prime rule with all childrens' books published by general interest publishers like McNally is that there are no rules. They were followed inconsistently.
Without any research on the title, I would fix the price of this at $25.00. It's in good shape. The pictures look like Tasha Tudor, Holly Hobby and other popular franchises. Clearly a knock off.
One last thing, the title page reads as if it is a translation to the German: Deutsch von (German by).
So look up the original author/book. It might reveal added value.
Only you can decided if that is enough money to be worth the time and trouble selling.
