Space Travel Guide
I wish this was in my reference box! I found it on Ebay yesterday but unfortunately it has a buy-it-now of $99.99 (£73.15) which is a little steep, even though it would be a great addition to my vintage moving dial collection.
It's a Space Travel Guide from 1958. It must have been a free giveaway with something and has an ad for Dellwood Milk & Dairy Products on the reverse. However, it's the dial I love - the wheel turns to reveal each planet one at a time, giving it's relative size and diameter compared to Earth. The illustrations are great too with really bold and vibrant colours.
Hopefully I'll find a much cheaper version at a boot sale some time soon!
Images from Ebay auction - copyright Designartistic.