The Norton version looks like a 2dimensional copy of the Hurricane. Wolfies photo link to the Hurricane shows off the curvature in the lateral direction. I think this is a good part of why the Hurricane looks quite interesting while the Norton version looks like something Daffy Duck would ride. No wait, it looks more like something Daisy Duck would go for.
The Ossas Stilletto looked great and went like hell back then. I still like the look of those bikes. I had one and couldnt break it, it was set upfor flat track racing at Portland by Dave Wildman, the local Ossa Triumph dealer. Dave is a great tuner, any bike he touches flies. He was for Triumph and Ossa what Herb Becker is to the Commando. The owner/rider could not handle the bike, kept falling at Portland, so I bought it from him, many warnings included.
I was fourteen at the time and chomping at the bit to get a bike with some real go in it, what a treat that thing was! Sorry for the diversion, the Ossa pic got me in the wayback machine for a minute there!
Glen