one thing i don't ever recall being discussed on the forum is front wheel speedo drive units.
i don't think i'm all wet here, if my memory serves me correctly, there are differences between early and late drive units. the parts do not interchange, if i recall correctly.
something with the difference in dimensions of internal parts. the end cap held on by small brass slot head screw being different. and the casting is different.
sorry i don't have pics. and i no longer have 4363 to compare to my earlier bikes. just seems a few years back, when i was rebuilding the drive unit on 232, i discovered it was different than 4363.