Hello Brian,  It sounds like the rolls you have are most likely cut
from National rolls.  You can tell by the following: look for the first
hole on the left to look like it could be a drum or castanet control
(this is the vacuum modulator hole on the National roll).  Also, you
will only find lock and cancel perforations on the roll, with the
exception of the rewind and cancel to play which I believe Don used the
standard A roll setup for.

Given the tunes are from the 1920's is also a good indication and if
the tunes are long -- say 3 to 3-1/2 minutes each -- if these things
are true then they were transcribed from 12" National rolls.

Stephen K Goodman - Professional Player Piano
& Nickelodeon Restoration Services
Tarpey Village (Fresno/Clovis) California, USA
http://www.mechanicalmusicrestoration.com/