What a wonderful thread, please keep it going!
Arensky's meeting with Ogdon makes for a wonderful and revealing story.
As for Ogdon's weight -- the souvenir book (?) that is included with the CDs of Ogdon playing Opus Clav. contains two sets of photos of John Ogdon.
One set shows him as noticeably younger, and not particularly overweight at all. Rather a nice-looking man in horn-rimmed glasses. (As my memory has it, anyway.)
The later pair of photos in the book show Ogdon -- many years later -- at the recording sessions. At this point in time he is very very stout.
As I myself am aging badly and gaining considerable weight, I am heartened by the amazing technical facility of Ogdon despite his prodigious girth.
If a beached whale can play the piano, that will be me in another few years.