Mickey Mouse Magazine file copy variations

[Pedersen Hans]

I am looking for information on the different variations of 1930s
Mickey Mouse Magazine file copies. The link below shows representative
examples that I am aware of. I'd be very interested in hearing about 
other types of identification marks.

http://www.hhkkpp.com/mmex.html

I know it is probably a longshot but any information about the history 
of these would be greatly appreciated.

Thanks, Hans