Good website for Norton info there, Marlin!

And yeah, you're right...it was '72 for the first disc brakes.

And Doug, here's another site I found for ya....

http://www.motorcyclespecs.co.za/bikes/Norton.htm

Yep! Just like a good Single Malt Scotch, you might call me "an acquired taste" TOO.(among the many OTHER things you may care to call me, of course)