Brooke is probably correct as to that being the group that got them first. The 8th AF in the ETO had priority for P-38 production after 9/43, and late November to early December is generally accepted as when the first of the P-38J models arrived in England. I'm sure the MTO was behind the ETO on that, and the 20th and 55th FG's were fairly large, so the groups in the MTO likely had to wait a couple of months, at least. The P-38 was a single source fighter, and production was limited because Lockheed was tasked with producing B-17s as well. The guy to ask about this is probably Guppy, or Widewing.