This page of a brochure appeared on fleabay, looks like you...
Armours in UK do replica mufflers and pipes.
Customers either love them or hate them though, depending on whether it fits or not,
if it doesn't fit its your fault !!
I'd be tempted to polish that up, change the pipe and muffler, repair any grazes and ride it.
(and paint that front fender black).
Replica fenders are available from India, but again they can be hit and miss. (?).
If you ride it while restoring it, its not going to spend years in the making.
Folks that have them say they are the best single that Nortons made, the swingarm frame is a good handler,
comfortable, and the engine is strong and torquey. And oil tight, with care....