So I have a 93 RR that is still running an R12 equivilent with really no problems, but there will be a time soon that I will be replacing the compressor. It is starting to show oil around the clutch, so any day I expect a complete failure at that seal. I also have a Defender 110 running the same A/C system as the 93NAS 110. Except it is using 134A. My RRC cools pretty damn nice. No real problems but I drive the 110 way more. That A/C puts out maybe 60F when its around 100F outside. Not too good. So I was talking with a guy this weekend and he mentioned 152A. AKA "canned compressed air". I have been looking this up and it seems way more effecient than 134A. I will be trying it soon in my Defender. Here is a link to some of the information.