How about oil for a air conditioning compressor? R 12 systems use a mineral oil, and newer R 134 A systems use a pag oil. one of these may close to the right oil. I would imagine that the mineral oil used in the R12 auto ac sysetm would be close to what they had back then. can be bought at any auto parts store in sm bottle. I'm pretty shure that's what we used in the old vacume pumps.
