which pivot pin and bushing for TO35?

The two bushings sounds like a field repair. (They left the factory with one bushing.) We always put two in to lengthen the time before replacement, on the theory that it will take twice as long to wear the two bearing surfaces as having only one.

Consider that this bearing carries the entire load of the front of the tractor, and front end loader if fitted - and with no lubrication. It is one of the very few weak points in the design of this tractor in my opinion.

We have repaired the axle and housing by building up with brazing and grinding with a die grinder. (Handy tool, that one - a king-sized Dremel.) It doesn't have to be a machined fit - just built up so it supports the bushings from flopping, distorting, and falling out, or to allow the pin to slide in.

The wear on the back sounds like the pivot pin retaining bolt was missing, allowing the pin to rotate with the axle. That bolt makes sure the pivot pin and axle bushings take the wear, and they are cheap to replace.

The two different pin numbers are interchangeable. The center hole in the earlier 183 221 M1 is machined to take a starting crank, the later 193 746 M1 won't take a crank. The bush - number 182 850 M1 - is flanged, and fitted to all tractors after s/n 4860.

Hope this helps.

You might want to consider adding 1/8" to the bottom of the gear shift lever (1-2-3-R, not high - low) while you're at it.

A weakness in those units was locking in low or reverse, caused by that lever popping out of the shifting blocks down inside. You can't shift until you go inside through the filler hole and correct it.

The lever can move up a bit in operation, and coupled with a bit of wear jumps out at the bottom end, usually on an agressive shifting movement.

The extra length seems to fix it. I've used both steel and braze welding - both seem to work.