Tim
A couple of comments......
(1)....Regarding your SOVEREIGN 350-Only checklist, you indicate that Bresnahan (batting) and Downey (fielding) as "confirmed".
Not so !
My research shows that these two subjects are SOVEREIGN 350  "No-Prints".
(2)....I'm quite skeptical of your claim that Crawford (throwing) "was not printed with a  SOVEREIGN 150 back". My experience in
 completing a  SOVEREIGN 402-card set (and since, going for a Master set) indicates that 12 (perhaps more)  SOVEREIGN 150/350
 subjects were Short-Printed with respect to their  SOVEREIGN 150 backs.
For example, the majority of the Wiltse (portrait, no cap) cards are found with the  SOVEREIGN 350 back. The  SOVEREIGN 150 card
 of this subject is rare enough that the SGC pop reports indicate that NONE have been graded. It took me about 5 years to acquire
 this one......
![[linked image]](http://i603.photobucket.com/albums/tt113/zanted86/awiltsesov150sov350.jpg) 
![[linked image]](http://i603.photobucket.com/albums/tt113/zanted86/bwiltsesov150sov350.jpg) 
Furthermore, Brian Weisner has already identified a Crawford (throwing) with a SOVEREIGN 150 back in Bill Brown's super-set spreadsheet.
Check it out ?
Regards,
TED Z