rust at bottom of rear door pillars beside rear seat belt mount, inner wings, inner sills, top and bottom tailgates.
chassis isnt usually an issue on range rovers,check the rear chassic along all 4 sides of each rail.
the engine is either 2.4 vm, 2.5 vm,200tdi,300tdi. both vm engines have 4 individual heads and gaskets, check for fresh anti freeze marks, vm is slow and thirsty, 300tdi is better not much to say on it.200tdi is noisey but great
gearbox's are zf auto-4 speed, borg warner auto-3 speed(would be quite late for this box but may be in)
lt77-4 speed manual(vm,200tdi),r380-5 speed m