I'm not sure if this is what you're asking and some of this has probably been discussed before.
Lundgren might be the most interesting print related subject in the set.
His Chicago variation was added late to print group 1 and the K.C.
variation was pulled early from print group 2.
With some of the information we have it looks like there were a few different stages
that the Piedmonts and SC350/30 and possibly SC350/25 were printed in.
There is a group of 16 (18 if you count Demmitt and O'Hara ST. Louis) subjects
that are the only no prints from print group 2 with AB frame, BL 350 and
cycle 350 backs.
Looking at this group it looks like Carolina Brights and EPDG could be part of
the earlier printing for print group 2. It looks like Bobby Byrne might have
replaced Lundgren Kansas City, Rossman might have replaced Demmitt New York
and Cross or Mowrey could have replaced O'Hara New York.
Attachment 291699