D-40 was a rather late variant. At that time they were already on P-47Ms and had been running them through their paces for some time. Because of this I would doubt they ever had any D-40s.
Not 100% sure, but that was my understanding.
What he said.
picsThe 56th FG flew C's through D-28's and possibly a few D-30's plus all of the M's in combat.
Hub Zemke went on leave in the Summer of '44 and, upon his return from the States, learned that the 56th had the opportunity to switch to P-51s and chose not to. He was a bit ticked off.
Anyhow, I think the NM D-11 is 61st FS, the "grey" D-25 and old default D-25 is 61st FS and 2 M's are 61st FS.
wrongway