Called USA Belarus folks to see what their list of parts/costs are: $455 for clutch kit (disc, pressure plate, throwout bearings); will compare that to getting some of these things rebuilt/machined locally (but local is a 100 or so miles away from me); also $20 for rear main seal (not necessary, but while tractor is split). Given parts costs, 6 - 8 labor hours, shop fees & such, I'm estimating around $2000, which I'll pay just for the benefit of watching it done by someone else the 1st time (and not getting squashed) ...
Others have suggested these ancillary tasks:
- inspect/machine/replace flywheel if needed (don't take off more than 12 thousandths)
- rear main seal, any seals at transmission/driveshafts
- find/repaint all fill caps, grease fittings
- clean off all leaky stuff (I thought all topsoil was being lost to erosion, but we found it all underneath this thing), and inspect anything else visible/accessible while tractor is split
Anything obvious missing above?