Thanks Kaz, this is an excellent idea & if I'd have stopped to think, it is the ideal time to convert the system to R134a, which will make any future servicing far easier, not being dependant on RS24.

Looking at the 471-1193, with a '97 mounting bracket, would seem to make sense to me, as I'm not sure the CL/pulley from my current unit is worth taking the risk with, just to retain the current '91 mounting bracket. I've been quoted anywhere from £150-£280 to re-con the current unit, so from a cost effectiveness point of view, it wouldn't be much more expensive, to upgrade to the '97 set-up. I guess a R134a re-gas will be cheaper than another RS24 re-gas aswell.

The evaporator was replaced a few years ago but the system hasn't been disconnected until i removed the compressor a few days ago. I've covered the open hoses securely to prevent moisture. So pretty confident there will be no moisture ingress into the system.

Thanks again.