having A/c clutch problems 84 brat

hi its been a while since i've posted i have a problem my A/C clutch. my ac compressor bearings were going out and i pulled another bearing pulley assembly of a Subaru at a junk yard and figured i could just replace the bearings with the ones from junkyard that were fine and i replaced it. but i have a problem my clutch keeps sliding inwards toward the A/c compressor and rubbing the pulley i have tried putting washers in there but it just wears through the washers.

what do i have to do to fix the clutch

or do i need to replace the whole compressor with clutches and all.

and second question is it worth the time to track down genuine r12 and charge it with that

or will freeze 12 and r134 work just fine.

i have an evaporator so i can do it either way.