I assume you are trying to collect all the T206 backs for the Phillies's guys ?
Doolan (fielding) is a real possibility with an AB 350 (frame) back; and, this is why I think so.......
Recall my A-B-C-D back design theory..........
A very consistent pattern exists with all 350 Series subjects that were printed with the combination of these 3 backs.....
AMERICAN BEAUTY 350
BROAD LEAF 350
1910 COUPON
So, my fellow Phillies fan.....I would keep searching for the AB 350 back on Doolan (fielding), since we know it exists with
the BL 350 and COUPON backs.
Best regards,
TED Z