Some days ago I realized that, according to this Gallet Clamshell advertisement, in 1939 there were booklets with the "complete waterproof Multichron line".
Perhaps some of these booklets still survive...
Do anyone knows anything about them?
Anyone has ever seen one of these Gallet Clamshell booklets?
If anyone could show an example of these booklets would be very interesting.
If they still exist, they are horological history.
Thanks in advance for any collaboration!