There are two places for the followers to wear ignoring the pivot tube which goes over the spindle. One is in the cup in which the push rod sits. Originally this was rare but with the bikes now 60 years old it is not unknown. Most frequent, and a fault almost from new, is the base of the follower. This should be flat, absolutely flat. Typically, before the days of stellited ones, the base would wear concave, very often with an unworn ridge left at one side where the follower had not been correctly lined up with the cam. If this wear is a few thou then it will not affect the running or performance. With the old case hardened followers and cams once you were through the case hardening then you were going to get very rapid wear of both the cam and the follower. It is unlikely that after all this time you will have the original followers unless the bike has been left unused for many years. If you have original followers and the depth of the concave wear is more than, say, 10 -20 thou it is time to get cams and followers stellited or replaced. The wear will cover about half of the length of the bottom of the follower and if it is slight it will be difficult to see without taking the followers out of the bike. If severe then it will be very obvious with just the light of a torch shining in on the side of the followers. The first type of wear mentioned, in the cups, used to be almost unknown, as the base of the followers always wore out first. However, with the advent of stelliting, the bases can now last so long that the cups can now be found severely worn. Good luck and if this is unclear then I can probably find a worn one to photograph.