Rhys (your #54),
Sorry for the delay in this answer, but I rarely stray far from my PPRuNe habitat in "Military Aviation>Gaining a RAF Pilot's Brevet in WWII". The Stearman comes in at p.117 #2331 on that Thread. There is a fair amount about my time on them at Carlstrom Field, Arcadia, FLA.
Sadly, I am no help in airframe numbers, as at Primary we only logged the dates of flights, and even in Basic and Advanced would only log the School-alloted numbers (eg "123") painted large to make the a/c easily identifiable.
Just had a hard look at the pic. We had a fixed-pitch metal prop on our Stearmans. Surely I can see a bob-weight on the hub here ? So it must be two-position (or even constant-speed ?). Is it even a 220 Continental ?
Cheers, Danny.