Rear brake cam lever / arm suit Norton models where lever points down eg shorter plunger model, cast stainles steel. Raw condition, the slot for the cam will slight adjustment with a small file. Norton used the same part number in the parts books for all brake cam arms post war eg rigid , plunger and swing arm until they corrected it circa 1954 but there are 3 distinct levers.
Original part number:
B4/469; E11M/469 - rear hub brake cam lever