Those Eldorados look like 1969 MY. I had a '69 Eldo to work on once; it actually was fun, coming up with an in-car electric pump to replace the vacuum pump that was original. Plus, to get the system to work right, a double-ended ball link had to be replaced; the local Caddy dealer found the last one in the GM parts network, in Toronto, of all places! Boss broke out the plastic, got it ordered, and once it was installed, it had working rear air assist suspension again!