I have never pulled one of my T&L .60s apart yet, but I believe you are correct on the sleeve issue. If you can't find a case, which I think would be the "bad" part in this instance, I wonder if the white paste that is used in electronics to help heat sinks transfer heat better would do any good. As far as the compression goes, it may need more running to finish seating the ring. Frank Bowman could tell you for sure, but I think Tom set the engines up with Bowman rings and about .0015 ring gap new. Franks rings are hardened and may take some extra run in. Make sure you have at least 25% all castor for breaking it in. All ST.60 parts are not generally interchangeable among all versions either, and the engines went through several changes through it's history. If the complete history of the engine isn't known, someone may have swapped out a sleeve from another engine that won't work with that case, or vice-versa. Randy Smith may be able to help you with the proper identification if you sent it to him. I don't know about the notching of the baffle. A guess would be to help turbulate the fuel/air mixture more when on the intake stroke.
Type at you later,
Dan McEntee