Thanks for the tyre loan Stu
I think rot wise after the Autopsy on the one we ripped appart you know where to look for that.
As Jai says, put a new timing belt in immediately. Listen for tappet rattle and popping from the engine, the usual black smoke from the exhaust that could indicate a worn turbo.
Check that the 8 setscrews that hold the cam follower buckets are all in place down the drivers side of the block (As I know now to my great cost). Check the serpentine belt tensioner as these are prone to fail over time, not a big job though.
R380, listen out for excessive whoning from the gearbox while driving, and a rumble in 1-4. synchro on 2nd will probably have packed in at that mileage but thats livable with. Watch for blocking of any of the gears while changing.
Check that the difflock selector works obviously.
As she will be towing the horse box then check out the towhitch obviously.
If it has sunroofs, then it will probably be prone to leaks up there, really mechanically of course it is virtually the same as the classic.