A/C Compressor for '90 Sundance ... need info

If there are any A/C pros out there who are familiar with Chrysler products
who could give me some help here, I'd sure appreciate it. I posted the other
day about problems I was having with the A/C on my 1990 Plymouth Sundance,
thought at first it was a coolant leak, turns out the compressor needs
replacing.

I posted that I had a compressor in hand that I'd purchased from a recycler
last year, with a warranty, that I was going to get my mechanic to install.
However, when I took it to my mechanic, he told me that it would not work,
that the mounting brackets and hose connections (especially those) were off
from where they needed to be to fit my car. Let me backtrack, this
compressor was not from a Plymouth Sundance, it was from another Chrysler
car that was "supposed be interchangeable and work" with the Sundance, but
as I said it wouldn't.

I don't want to buy a new compressor for this "running around town" car, I'm
looking to get another recycled one. And I'm willing to spend a reasonable
price to get one. The thing is, I'm now leery of ordering another one sight
unseen, because I've followed up on a couple of responses I got from
submitting online parts searches but when I talked to the folks, it turned
out that again, these weren't off an actual Sundance, they were off other
Chrysler products but were "supposed to work." One recycler did list three
different A/C compressors for a '90 Sundance on his site, had all three in
stock that actually came off Sundances, and told me that the one I needed to
get depended on my car's VIN and mine was a "D."

Can someone give me some guidance here? Are the A/C units actually that VIN
specific? I checked for new compressors at AutoZone, Advance, O'Reilly,
etc., and they all listed just one part number for a compressor and clutch
unit for a '90 Sundance, didn't say anything about the VIN.

And are there some units from other Chrysler cars that will actually
interchange with a '90 Sundance? Will a unit from an '88, '89 or '91
Sundance work? I've looked online and can't find anything with the actual
Chrysler parts numbers so that I can cross-check.

Are there any kind of adapter kits, etc., that could be used to make one fit
that's a little bit off?

My mechanic is ready and waiting to install a new compressor and clutch on
this car, all I have to do is provide him with one that will work.

Again, I would appreciate any specific guidance here. Thanks!