From my experience with cars, the AC Compressor seals start to leak if the compressor is more than 13 to 14 yrs old, so if you recharge them, the new charge only makes the seal worse--and then you lose everything~~
I assume the compressor is a Nippendenso, I've only had the car a few weeks, and quite frankly, though its an 87, I am embarrased to drive it because I feel like some guy who just won the Lottery--I've never had such a clean white glossy car before...