I have been looking at a boat for a while and the owner is ready to sell. The boat is equipped with an OMC King Cobra drive unit (cone clutch style). I'm undecided on keeping the drive on the boat for a while or selling it and swapping in a merc system. Either way it goes I need to make sure everything checks out ok with this thing so if needed I can use it as leverage when negotiating price. Anything I should look for? Tell tale signs of abuse or failing parts?

I may be wrong but I think the Cone Clutch cobra transom assembly has a different transom cutout than the regular cobras .If you intend to replace transom anyway ,no issue .All the other cobras have the same cut as an alpha /bravo.

first thing to to verify you have a king cobra...alot of parts for that drive are NLA....
http://www.allamericandriveservice.com/OMCCobra.html

It is a king. It has the big bump on top instead of being smooth