PART NO.  SPL.PAGE  DESCRIPTION                                                           
ATB7229   15.H.2    Seal -oil 2  (rear wheel hub 1500)
ATB7354   16.H.4    Ring -oil seal (2) -(rear hub, 1600 and 1600-MK-II)

Alternate part numbers:
121-400 --- Moss Motors, USA

These parts were originally flat rectangular section O-rings, later changed to round section O-rings. For additional information about these O-ring seals, including dimensions, see Rear Axle tech article RA103.htm