I have discussed this case with some other AC guys, and it is possible that a shop that can rebuild the famous GM A6 might be able to overhaul the OEM comp. (which is a semi-hermetic) Or perhaps a shop that overhauls semi-hermetic comps as used commercially such as a Copeland semi-hermetic. Is there...

Well said, Tim.
Hopefully you are not too offended.....
I think he owes you an apology

I see an overdrive relay so you won't be anywhere near 4K RPM

"This forum is highly outdated."
In one man's opinion. If it is so outdated, why bother coming here?
You can resize pics in Paint (Microsoft basic photo editor) with 2 mouse strokes if you don't have a broken hand

Per Bohica, "Engine speed range and drive sizes matter. If you don't have enough compressor volume the system will be awful." Your original engine is a long-stroke low revving engine, typical of the day. All the torque is down low and red line is probably 3K at best. Any more than that and...

Brad or John or Ice there is a new thread on here about a re-engineer of a vintage '53 Packard system which has your name all over it. Possibly you have seen it.
https://autoacforum.com/viewtopic.php?t=14942
Regards, Dave

You have a most interesting project at hand. I believe Packard was the first to offer auto AC. It is a shame that you want info from us but won't take a few minutes to resize your pics. I am of the opinion that the expansion valve will work as is. There are several other highly knowledgeable techs o...

From what you describe it sounds like they did OK.
Evacuation/recovery of refrigerant of a system with a pro machine seldom removes much oil at all.

Were you able to see any 'wet' areas on any fittings or hoses? Or areas where dirt had collected? (leaking oil tends to attract dirt)

"Do you think it was getting damaged by running it with such little refrigerant? "

The refrigerant carries the oil all through the system. Of course, only the comp needs any oil. So, yes a comp can be harmed by a charge level that is too low.
As you stated, only time will tell

send Tim an email with the make model year of car and ask him for everything from the firewall forward. He will respond, he is very accommodating. Then you can compare your prices. But he has very good quality prices at very reasonable prices. This type of repair , while aggravating, and costly, is ...