G'day QSR, is it for restoration/display or just to keep going for mowing duties?
Any 6" front wheels from a Victa spanning decades will fit. The earlier ones like yours are heavier as they have more rubber in their construction, where the later ones have mainly plastic with a thin layer of rubber. They look identical to the untrained eye. The heavier totally original type you have are harder to find, but the later types should be fairly easy to obtain off another mower.