Dummy me, i was thinking of a rear-wheel drive car. All the pulleys are on the passenger-side, "my mistake". Anyway, The only one on the bottom of a Park-Ave is the AC-compresser. This would make sence because it is kinda common for the AC-compresser to have the pulley break. It (the pulley) goes through some stress when the AC is turned on. Fixing it is a challange. I would get a compresser from a local salvage yard, replace it myself and re-charge it myself. However, i think there are some laws that will be broken by doing this in a back yard. I'm not too sure on this because your charging stuff (R-12, RU-956?), whatever it is, should be friendly to the ozone unless it is freon and no shop has changed it over. There might even be a law against changing the friendly stuff? A-lot of "if's" there. It has to be changed, lines have to be removed releasing "the gas". It is a good idea to replace the belt since you have it off. Sorry i dont have more details.
Rick