RAF against Japan
Don’t know how significant this is to the discussion, but I think real planning for “after Germany” began around April/May ’44, shortly BEFORE D-Day. Sorry for the imprecision, but I’d have to do some digging to get a clearer idea.
re building B-29s, summer of ’42 [yes, I’m jumping back!] was a time of much planning in terms of resources, etc, and I do recall a comment which I think was about then (might have been slightly later) along the lines of “If we’re going to focus on one US type to build here, it seems like the B-29 would be the one to choose [vs. the Merlin Mustang].” But I don’t know anything directly about the idea of building B-29s in UK.
bob