From 1965, a different machine was produced for a short time by parent manufacturer AMC, based on a Matchless but badged as Norton ES2 Mk2.

From 1947 the ES2 had an innovative hydraulically damped telescopic front fork and race developed rear plunger suspension.

From 1959 it used the Rex McCandless-designed featherbed frame, with upgrades including an improved AMC gearbox, revised cylinder head, crankshaft-mounted Lucas RM15 60-watt alternator with coil ignition and an 8-inch front brake with full width hubs front and rear.

A Matchless-based machine with Norton badges, it was produced for two years before final discontinuation, coincident with the commercial failure of the AMC Group.

A report in a 1980 UK magazine stated:[8]The slow but immensely likeable Featherbed-framed 350 Model 50 and 500 ES2 Norton ohv singles were dropped and in their place appeared the Model 50 MkII and ES2 MkII, or, with Norton badges hastily tacked on the side, the Matchless G3 and G80.