He's probably got no connection with Vincents (as far as I know), but I remember seeing him at the Laguna Seca Raceway, CA back in the early 1990s.
He was treated like a rock star, and was always a real favourite of mine.
If I lived a bit closer to Mick, I'd be up there like a shot - he's said to be a thoroughly down to earth and a 'real nice bloke'.
Last time I heard anything about him, he was involved with something to do with medical motorcycles in Africa.
Saying something like 'Why should any VOC member be interested in Randy Mamola? Has he any connection with Vincents?' is like saying 'Why would any VOC member be interested in the Isle of Man TT. The Vincent connection disappeared years ago'.
Just my thoughts.
Graham