I can help you a little Bill, the neat disc brake conversion was done by Roy Cross, in fact the entire Comet was put together by Roy Cross, I could tell you a lot about this bike as I came very close to purchasing it, but my interest coincided with the first Covid lockdown, and then other events overtook me, but I can tell you, it is a very interesting bike, fixed AMC/Norton gearbox with primary chain adjustment converted to twin style spring plate slipper adjustment, no engine shock absorber as there is shock absorption in the clutch, coil ignition, fully sprung, probably loads more interesting info, I had Roy's build sheet on my computer, but I think I deleted it in error. But it is a very nicely put together bike.