It's 'cos we have catholic tastes Peter!
I've got one mid-60s Norton twin and a Norton-engined AMC desert sled. I've been impressed by availability of all the oily bits for them, I must say, and I especially like Andover Norton for 'helpful'. (Not that Feked haven't also been good, especially for one particular exhaust system.)
Should add I have also been happy with the Beesa oily bits I've had from most of the well-known suspects. Seem to do what what they say on the tin anyway as it's a darn reliable machine. Some parts are harder than for Notruns though!