Yep it's a LTS Carbon and it looks bad and downright sad
Rare it is as it's GT's first production Thermoplastic mountain bike
Components are awful, all that remains of the original XT parts are the rear mech (which looks strange
) and possibly the V brakes. But it also looks like this frame might have a couple of other problems.
No front mech and looking at the frame I can't see the mount for the mech. This actually screws onto the frame and if it ain't there you are going to be limited to a maximum of 9 gears. You can see what I'm talking about on this pic. The mount is above the BB
Very very very unlikely you will be able to source a replacement part. I would have a go trying to fabricate something using a seat tube from an old frame or, you may be able to fit an E type front mech. Not 100% sure that this is possible though
.
Also what's going on with the cable routing??? Looks terrible and is wrong should be directed internally unless there's a problem there
Possibly the owner doesn't have a clue and has missed the holes situated on the headtube and/or does not know what they're for.
Looking at the faults, would I buy it? Yes
As long as that carbon is OK it won't take much to get this looking good. Even if the bearings are shot these are readily available. Gil_m will sort you out some decals. You can get some decent XT M739 components and fork stuck on there and you'll be nearly there.