For the first time in about 2 weeks I have finally had some time to work on my Hippo. All the lights now work and the OSR brake is no longer binding!
The faulty NSR brake light fault turned out to the connector inside the lamp assembly: the contact just needing pulling up to make a decent contact with the bulb.
The faulty reversing lights (I'd already replaced the faulty switch) turned out to be a severely corroded loom-side bullet connector. I hadn't noticed this before because it is dark down there in the engine bay! LOL
The OSR drum came apart okay - I had to release the ratchet quite a lot to get the drum off, although the drum itself is not badly warn. The inside was caked - I mean CAKED - in dust and corrosion. But the brake shoe friction material still had 3.4mm of meat on them. The slave cylinder looks to be a pattern part, but it was dry and the seals in good condition. I basically cleaned everything up as thoroughly as I could and reassembled - and now the car will coast when the clutch is depressed. Reversing now doesn't bring the car to a halt at idle and generally things are looking rosy.
I do need to adjust the handbrake now though - I wonder whether a PO tried easing it off in an attempt to release the rear brake??? No idea, but hopefully that should not take too long
A couple of minor and perhaps not so minor things:
1. The rear drum is making a noise after I've reassembled - that soft chuff-chuff of something rubbing: have I put the drum back on square or done something else wrong (I'm much more comfortable working with disc brakes!)
2. I've noticed that the TC (and occasionally also the HDC!) lamp will momentarily come on and then extinguish. Any thoughts? I'll need some diagnostics on that I think...
3. The digital clock adjustment doesn't work - despite disassembling and cleaning the button contacts. Annoying.
Oh, and I've still not completely sorted the malodourous interior. But Fabreese soft furnishing de-odouriser seems to be the best product so far...
I'm going to take it for an MoT this week - let's see what it'll fail on! I can't see anything too obvious now, so who knows?