In my pursuit of rebuilding a pony motor governor. I have noticed that there are at least four different governor bodies (5B5105, 5B5107, 4B2460, 4B2461) according to the manuals. I have came across two (5B5105 and 4B2461) in my possesion. The 5B5105 has the slotted holes to adjust the belt. The 4B2461 and regular round holes and uses the shims under it to adjust the belt. Has anyone seen the others and are they all interchangeable or just the slotted one interchange with the other slotted models???