According to Lake's book "Phantom Spirit of the skies", page 221:
"The RAF strike attack aircraft......could also be armed (Nos 14, 17 and 31 Squadrons ) with US-controlled B57 nuclear weapons".
I certainly heard one or two cryptic stories from the "old timers" during my time on the beast in it's AD days that, whatever the variant, it had certainly been an American controlled weapon
. Anyone prepared/able to spill the beans, or at least some of them??......