A further Model 50 was briefly produced by Norton parent-company AMC during 1965 and 1966 using a re-badged Matchless.

[2][3] Designed by Edgar Franks in 1933, the first run was almost identical to the Norton Model 18 except for the bore and stroke.

Halted by World War II, production of the Model 50 single restarted in 1956.

After 1959 the Model 50 gained the Featherbed frame, Lucas RM15 crank-mounted alternator (upgraded from magneto/dynamo used on 1957–58) coil ignition and improved lighting.

In common with other large Nortons, the frame was updated to the 'slimline' version with revised styling in 1961.