Had one of those "slip back a few (!!) years" moments, and wonder if Ron May is still around? His Triumph (he insisted it was a speed twin....) was ridden by a host of riders in the 70s - Ray Knight, Roger Bowler, Graham Bailey (I think). He was a hard taskmaster as a sponsor, pushing you to do as many laps as possible in practice (and of course the race) and entered it in all manner of classes - Production, Senior, Formula750...
He was one of the archetypal tuner/sponsors, in the mould of Francis Beart - brown warehouse coat, beret, dour sense of humour.
His bike won more replicas than most - maybe more than any!?