the clutch itself has a bearign that you can change in the delphi/harrison unit - the magnet coil is a push on fit, if scrappies wont sell you that then get some from outside Pakistan there were millions of these compressors made.
yes - harrison V5 is very advanced when compared to these same sanden units, the great part is that once the system stabilises (cabin cold enough) the compressor eases off the engine (very little load)
r12 doesnt behave well in PF condensers because it does require some flow speed to work, you may experience freezing if given the chance.