:word:
Most everything else has been said too:
Rust on the frame rails (more towards the front), rust on the hatch if it came with a factory spoiler. If it came with a factory sunroof, be very thurough checking around there. Make sure the headlight motors work in both directions (unless you plan on doing a front end conversion). Auto-seatbelts can be a bitch too (try to find a manual setup from a canadian car).
As for the LSD, if the car came with HICAS, it has an LSD. If not, there is a VERY slim chance that it has an LSD, look for huge cooling fins on the LSD cover. I think there was some form of marking on the LSD differentials as well. Ask F Dot (AddictedtoBoost), his 240 had an LSD an no HICAS.