Tim,
Wayne really nailed it - the bottom end of the engine is the driver on the overhaul. Cylinders are repaired or replaced only as needed. Don't do an overhaul unless it is needed and the way to tell it is via oil analysis, borescope examination of the cylinders and data from an engine monitor. You've got good oil analysis, which is a huge plus. It appears the engine is effectively mid-time.
Suggestion: use the odd engine "overhaul" as a negotiating tool on price (this is definitely the time to buy) and make the deal contingent on an acceptable prepurchase examination. Have the cylinders borescoped (do a compression test but recognize that it may be art more than science as two mechanics doing compression checks one after another may get widely differing results). It looks like a very nice airplane. I did not see that it had an engine monitor (maybe I overlooked that part). If it doesn't, that would be, IMHO, a wise, immediate installation as it may pay for itself in catching little problems before they become big and help that engine run a long, long time.
You might also want to set aside about a quarter of the purchase price to cover the things that somehow invariably go wrong the first year no matter how careful you are.
Also, heartily concur with Wayne's recommendation to join CPA; excellent organization with tremendous technical information. Mike Busch's maintenance articles are themselves worth the price of admission. (His column in AVweb is also excellent reading.) He's running a T310R with engines that are 1000 past TBO and going strong - LOP operation, oil analysis, borescope and engine monitor data analysis regularly.
Good luck with it,
Rick
