Are the different Duo-Art Audiographic roll leaders specific to
different years of publication?  I.e., is the leader with the entire
international committee of earlier origin than the one that omits the
international committee?  I have no examples among (my many duplicates)
of rolls with both kinds of leader.

I would also like a definitive answer to the different letter prefixes
to the serial number, i.e., what is the "U" series?  What is the
"A" series?

Bruce Grimes