Jeff, here is a picture of my T65 several years ago after I gave it cosmetic make-over. It is due for an overhaul now and has not been used for quite a few years. I found it locally advertised in the newspaper as a "BSA with Triumph engine." I wasn't sure about it but bought it anyway. It was in poor condition, half stripped and I later found one piston had a hole burnt through it. It is still on standard bore and I fitted a used piston and sorted out a few issues, wired it and away it went. It didn't have a tachometer fitted and looked lopsided so I fitted one.
I understand South Australia Police imported a batch of T65's and there a few surviving in this country. I was told that several were converted to Triumphs for easier resale. Mine is the 35th produced.
Fido, the Norton engine when dynamically balanced is as good as any BSA engine as far as vibration goes. I get all my engines balanced and I am very happy with the improvement. I find the Norton engine more responsive to throttle and freer revving than the A10. Having said that, I only have one Norton compared to a shed full of BSAs.
Trev.