No hassles...
to tell a GR from a GPX, you can use the full code with the chassis number, see CJ's post
here, the code on the right hand side will tell you exactly what it is.
Also, see the
buying guide for pics of the 3 engines.
Not a huge amount to choose between GR and GPX though, GPX has a few more horses, and there's the legendary MIVEC roar of course. Some would regard the GR as having the edge with regards to reliability, but having said that the GPX tends to be pretty solid itself once its looked after any bit reasonably.
I've never had to take a mirror off the FTO, but from what I've read its handy enough. First remove the internal door panel, about 6 screws iirc, then ease it off bit by bit, guide how to do it with pics
here.
You'll of course have to remove the electrics from the mirror, but its just a matter of 3 bolts I think? It should be obvious enough once you have the inner door trim off anyway.
If you need to get a replacement, Steelroe & Ricerocket are the guys to talk to, they might be able to sort you out with a used one (or even a reasonably priced new one maybe). Alternatively they tend to crop up on ebay every so often.
Kev.