Thanks very much for your advice. It's not going to happen immediately, but it is one of the few remaining problems I have to sort out on the car. It's great to get an idea of what I need to do after a couple of years of ignoring the problem completely by not driving the car!
I just have too many projects on the go and not enough money.

Still, when I get around to sorting this out, replacing the alternator, and getting a little bit of bodywork sorted out, then the car will be suitable for driving every day again (not bad for a 25 year old car).