I would leave it in place...even if it doesn't work. Rarely do you see cars this old with original, factory a/c. Working or not, it adds to the interest under the hood! As for re-sale. A buyer would much rather have it in place and in tact than a box of parts they are 'told' are all there, and some photos they 'hope' show all angles needed to get it back together. As YY1 said, "...just let it spin."
You didn't say what it is, or isn't, doing.
- Does the compressor engage when you turn the a/c on?
- Do you see bubbles in the 'sight glass' with the a/c running (and the compressor engaged?
- Has the system ever been opened that you know of?
If the system has never been opened, the compressor engages when the system is turned on, and it simply blows hot air, it likely just needs to be serviced...nothing but Freon added. Some places may even have the R12 still. If not, they can evacuate the system and replace with R134a...without changing a thing! It's a chance I would take if the compressor engages. You could change out the hoses if you don't trust them.
