C 40,505 (A2S4) and C 40,979 (AS4):
Brake adjustment holes in drums circular and same size as holes in road wheels.
Rubber plug used to seal both holes and to be put in place after tightening wheel on drum.
C 43,849 (A2S4) and C 43,898 (AS4):
Final-drive ratio raised to 4.875: 1.

March 1954:
Wing-joint mouldings only available off the roll rather than ready-cut lengths.

E 49,357 onwards:
Modified carburettor incorporating a new type of discharge nozzle and choke tube to reduce tendency to ice-up.
C 49,778:
New propshaft with larger universal joints. New bevel pinion flange on rear axle to accept propshaft.
E 56,573 onwards:
Longer, stepped dowels used to locate clutch on flywheel.
Larger holes in flywheel to receive dowels.

October 1954:
Rear reflectors fitted to conform to new lighting regulations.

C 64,411:
New horn of improved performance