At first I figured "the OP said the tractor is in real nice shape and if he had the ability to do it do the work himself, what the heck why not have some fun with it".
Then i looked up a rebuild kit from this guy on eBay who has pretty decent prices.....
AUDIBLE GAAASP.....
FOUR FRANKLINs and a GRANT for pistons, rings, rods, gaskets and seals for a CV25. Took the fun right out of it, OUCH!
http://www.ebay.com/itm/OEM-Kohler-C...wAAOxy4fVTC~e-