Thanks, Aratoga, that's good to know
I've had a look at the diagrams in the handbook (it has a lovely fabric bound handbook that smells of oil and libraries) and it doesn't look too challenging.
The good news is Gerald's home! I picked the car up yesterday and it's looking beautiful.
So far it's had a new (reconditioned) engine and gearbox, a new clutch (it wasn't essential, but it was a hell of a lot easier to have it renewed while the engine was out), wing mirrors fitted, a new radiator, some new pipes in various places and sundry work with the service. And they gave him a bloody good clean, so it looks fantastic!
However, there's now a worrying knock coming from the nearside rear wheel... Going to have a look at the bearings (the front ones need looking at anyway, there's a bit more play than I'd like there) next, and the brakes, and... (ad infinitum).
The funny thing is although I'd never really thought about it before, last night I realised what Setright meant when he said the Herald's suspension makes it feel like it's going to fall in half, even though it has a very sturdy chassis. It doesn't feel like it's going to fall in half, but it is quite independent... and yet, for an old car the ride's not half bad. And the chap that did the engine said it's one of the straightest, cleanest 1200s they've seen. This pleases me immensely, because it shows I judged it pretty well when I saw it. The engine problem was, as I thought, something that couldn't have been picked up without dismantling it, so I feel vindicated, if considerably poorer.
Of course, once I eventually pass my driving test, I now have the job of running it in before I can really take it anywhere...