Well there's the first problem - a lead broken off the main relay by my detailing:
Fixed that connection (above), but alas, still no starting.
Disconnected the fuel line from under the regulator and, when turning over, nothing comes out - so it *is* a fuel problem.
Interestingly, when left for a day or two, it does catch (then die) at the first turn, which indicates to me a) electrics are still fine and b) maybe a bit if a leaky injector or six...
To be continued!
T.