Hi,

I think there is the adapter plate, that you are referencing, that relocates the the power steering pulley forward to line up to the crankshaft pulley. below.
You use a longer belt that goes directly to the left and down to the crankshaft pulley..
Only need to remove the A/C belt and all else stays put until you need to fix it permanently.

The mechanic should NOT have refilled the system as he knew it had leaked out before.
ITS illegal to just discharge refrigerants into the air, so that was a lousy way test out his suspicion.
Apparently from his statement, about it being expensive, he knows he is either going to make big bucks or he is not going to fix up your old car.

I'm amazed that he had R-12 or another replacement, to toss in there, but it was your money!
Last I knew it ran about $8.00 a pound. You need about three to do the complete job, if one is carefully in hooking up.
Having air conditioning is a luxury and there are lots of ways to pay for it!
So Sad isn’t it?

It seems that the pump is still working, so it’s not broken!
You need to look for fresh thin coating of oil seeping from some joint or line itself.
Sometimes, it’s just the high side receiver with the sight glass in it.
I have found that the bracket that hold the unit is mounted in foam rubber and rust happens under it.
A new receiver is just over $20.00 for the last one I got from NAPA or Four Seasons.

Phil