Another idea which would have probably helped in both scenarios would be Churchill beating Attlee (for potentially more Marshal Plan aid) as well as the UK accepting (instead of rejecting) LBJ's* offer during the mid-1960s to get involved in Vietnam in return for the US potentially cancelling the debt from the Anglo-American loan (that was not repaid until 2006 in OTL).
Perhaps in the case of the former, it would have allowed for the UK to adopt Westinghouse PWR designs with an overall more-solvent UK embarking on an earlier analogue of the Messmer Plan?
*(From an old thread by michael1) - LBJ offered to pay substantially
more (certainly at least hundreds of millions of dollars and possibly billions more) than the cost of any British military force and Britain still said no even though this was at a time when Britain was desperate for dollars. The offer was in the form of additional assistance for the £ rather than directly to pay for British troops, but it still potentially involved large sums being transferred to the UK which could then be used as the UK saw fit. It never even got as far as discussing real numbers because the British just said no.