Project bike

I've been giving some serious thought to selling the Norton and putting the money into something older... and a lot rougher. I want something from the 50s. Something I can get running and legal, but keep it really rough and stripped down. A 'rat bike' I guess is what I'm talking about? Although I'm thinking more cafe style than bobber, which rat bikes tend to be. I do quite like this one—half cafe racer/half bobber (apologies for bad referencing but I can't remember where nicked this photo from?)...