Just about the only thing that stayed the same was the bore of the slider and the fork bushes.....
The spindle mounts can be pinch bolt and LH thread on early models, plain hole and threaded for Ariel type all alloy hub, and finally clamp type lower mounts.
Mudguard mounts for the fork brace can be two holed tabs to the rear or two threaded spigots, one above the other.
The lower mudguard stay lugs come in fore and aft variants, or just a single threaded mount to the rear. A65 type are similar, later variants having a hole into the slider above the spindle position, for the damper assembly.
Early variants also have a cup to the rear as a brake plate anchor, omitted where the 8" single sided brake is used. This hub uses a torque arm back to the fork brace/mudguard mount. Late type use a welded on lug to engage in alloy brake backplates.
The fork sliders are also used on other BSA ranges, B ,M, C pre unit, and on later unit ranges.
So it is not as easy as you think, and defining the correct variant for the model in question is the first step. Pulled threads, rusty bore, dings and dents and a poor thread for the oilseal holder are some of the more common pitfalls.
Swarfy.
