I think A.J.S. and Matchless as well as Ariels fitted the same type of clutch. It needs to be the 5 spring and 5 friction plate variety, so the basket must be 1.5" deep and be riveted to a 40 tooth sprocket. The Rider's Handbook illustration is wrong. Have a look at the Spares Co. website. It shows the early and late types of friction plate. The late type fits the later 1954? on drum which is a better design. The website shows the earlier design in the exploded view as well. If you buy the Surflex plate set, available online you may have to start with four friction plates as they are a little beefy.