For what its worth, (and talking RHD Jeeps) my TJ already had the AC comp removed, but I wanted to for onboard air.
So went and pulled one from an XJ, which was located down below the intake/exhaust, on a bracket which I didn't end up needing.
Went to install on my TJ, up top on the LHS, and found the front two bolts lined up perfectly, the pulley was parallel and correct depth, but the two rear bolts were out. Out by about 2mm.......
No idea why or how, but they were. So I torqued down the front and made a makeshift bracket to hold down the rear. I have a spare belt that can bypass the compressor if anything were to go wrong (although no issues so far)
Not sure what model compressor it is off the top of my head
Edit, its a Sanden U4636