Code-A-Graph Cipher Wheel

"Great battles have been won and lost; empires have fallen; great men have lost their lives and others were made famous, because of the information revealed by mysterious secret ink messages."

How could any kid resist this? This little wheel was copyrighted in 1934. It measures 2.625 inches across. It is made of a decent sort of cardboard (not coated, though) and is in great shape considering its age. It is accompanied by a little booklet on invisible ink and two bottles of fluid for writing and revealing invisible messages. Sadly, the bottles are long gone. I wonder what they had in them?

This little code wheel is a real gem, don't you agree? I would have loved to have one of these. This is a pretty sophisticated little device, really. I have reproduced the entire booklet for your pleasure below. Note, also, the other products put out by Playgames, Inc.