wuzak
Captain
Maybe they need to make the Merlins in England. So far as I know the only firm in the US which made Merlins was Packard, and I think that applies for Canada too.
A production facility was made to build Continental I-1430s. Late in the war that factory began producing Merlins, having been used to produce radials for a time.
If the USAAF had given up on the I-1430 earlier the factory could have started building Merlins earlier. A useful number of Merlins could have been built at that facility.
Due to the deal they made some of the Packard Merlins were going to the UK, the rest (once they got to the 60 series) mostly went into P-51s.
Most went to the UK. For Lancaster B.III, Canadian (and Australian) built Mosquitoes, and Spitfire XVI.
The original deal was for 6,000 Merlins to Britain, 3,000 for the USAAC/F.
Could Allison make Merlins?
They could, but that would most likely screw all the V-1710 powered aircraft, require a changeover period and a lot of modifications for aircraft to accept the Merlin.
Possibly a better option would be to make low-level performance Mosquitoes using V-1710s.