I bought a L2600 last week with over 3000 hours. No leaks, no smoke, starts and runs great. 3K hrs is a lot but the seller was asking $2800 so I didn't pass it up...and its in great condition!
Think I'd do a complete fluid and filter change right off to get started at square one and then stick to the Kubota maintenance schedule in the manual.
Kubota's are just as good as Deree's and I know a couple Deere's that have rolled over the hour meters and are still running fine. All in how you take car of it.