I am in the process of getting parts together to have my 20 spline T50 rebuilt (in a 1974 TA22 with a 2T motor)

I have found the right rebuild kit that has the gear bearings, synchros, seals and gaskets and am now on the hunt for the less easy parts to find.

the main hurdle appears to be making sure its the right part for the 20 spline and not the later models as it appears the input and output shaft bearings are a different size and there are differences in the selector hubs and idler bearings

one I'm not sure on whether it is the generic to all versions of the box or different across is the generations is the clutch thrust bearing and clutch thrust bearing hub, is anyone able to provide some advice?