Can't advise on whether the later 1993 condensers will fit; but, if the condensers aren't leaking I suggest that you purchase a fin comb, spray the front surface of the condensers with water to soften stuff up and get down on your side and spend some time cleaning and straightening the fins. Much cheaper than new condensers and a recharge and have to deal with the whole refrigerant change thing (1991 - r12 ?).
When I first got my car, operation of the air conditioning was marginal. I got down in front and discovered that the condensers were loaded with dead grasshoppers. I made the mistake of trying to clean the grasshoppers off with a garden hose - rehydrating desiccated grasshoppers results in a smell that is 'special'. After the smell had dissipated, I took the fin comb to the condensers. It probably took 2 - 3 hours to get the fins cleaned and relatively straight. I purchased a set of Dali condenser guards (no longer available) to make sure that I was not going to have to repeat this. Operation of the air conditioning has been just fine ever since.
