Rigid Frame Dimensions

Dear All,
I am trying to find the engineering dimensions for Norton rigid frames. I have found quite detailed ones for BSA and Triumph rigid frames but nothing for Norton ones. Any one know if they are out there?

Phelps.

I've been keeping an eye out for something similar,
but never heard of even a whisper of one.

The NOC, or members thereof, are said to have all sorts of stuff,
but very little is ever likely to see the light of day. ?

Nortons have had a number of ownership changes over the years though,
and such turmoils are never good for record keeping...