I haven't been on this site for a while since I went back to work, but I was intrigued by the quiz forum. Just my kind of thing!!
Totally off the top of my head, and without any recourse to old books or programmes etc, I agree with Helen's claim of him being in "disguise". I can remember him racing in the Manx and Southern 100 between around 1973 and 1976, on a Manx Norton with a white fairing with "Buxwell Equipe" written on the side. In about 1976, he remained on the island after the Southern and appeared at Jurby Airfield meeting, another rider named S. Jeffries also rode a similar Buxwell Equipe 500 Norton at the same meeting.
I was told by a reliable friend of mine that he wore the long wig and sunglasses as disguise because it was in an attempt to keep the fact he was racing on the island hushed-up, for whatever reason. He used the name B.T.M. Banglestein which was in reference to a track on one of the Beatles albums called "test tickles to Mr Banglestein".
I would imagine that he was one of those who was forced to cease riding in the Manx when he reached the age of 40, which back in the 70's was the upper age limit for competing in the MGP. Many riders who were at the peak of their careers were never seen again on the TT course, either because they were unable to compete in the TT, or had no desire to do so.
OK, like I said, all that info is straight from the top of my head. Am I right, or can someone else correct me or add any more?