Thanks for the info. I got back w/the Shop today and the service manager (a 25 yr heavy equipment wrench) came out and helped clarify the good & bad. It looks like I can get another 500 or so hours out of the under carriage by replacing only the rollers & he's going to search around for some used tracks as they are fairly worn. That gives me at least 5 - 7 years of work before spending serious money. Motor's been replaced and clutches are good; tranny shifts fine.