That's what I heard; that the B-52 was the first to be called a buff.
i first heard someone use that term to describe a B-52....which makes more sense IMO
NNNOOOOOOOOOOO!!!!!
The term "BUFF" can be traced back to RAF spitfire pilots describing the Lancasters as they watched them crossing the channel early in the war. This is according to an interview with spitfire pilots for the series Spitfire on the BBC. And yes, I am referencing a television interview.
And the brit in the interview used Big Ugly Fat Fellow.