Well, I couldn’t wait until Sunday – so I’ve pieced the RiscPC back together and fired it up…
And it works absolutely perfectly. Turns out it’s actually a Zip 250, which is nice – and all the insides work splendidly. The keyboard I recovered at the same time is shot, sadly, but it’s just a standard PS/2 unit and will be simple to replace.
All it needs now is a clean and tidy and it’ll be as good as new. Not bad for something that was going to end up polluting some landfill site somewhere…