Mild, reasonably engineered thumpers but rather slow for modern road conditions. Go for the most recent model possible as they had tougher engines and much better chassis and brakes, avoid nasty handling rigid framed versions. Final versions from 1962 to 66 were particularly well done but watch out for bodged engine internals as they will run with all kinds of nastiness inside the motor. Also Matchless G3/80.
1945-66 348/497cc OHV single 16/23hp, 70/80mph, 95/85mpg, 350/400lb