Well, I've been playing with the (Vortex) loom spread over the chassis for a couple of weeks and am making progress.
The ten-page Vortex installation pictorial MS Doc at least gives an indication of what is what even if a few connectors left me scratching my head for a while! Resorted to Dymo labeller on each connector to keep track.
Had a problem with no headlamp flash on the original loom despite two different column stalks and two "change over" relays in the inboard fusebox. Hmmmm....
Well, I never much liked the early 827 "paddle" lighting stalks so I went out and found a slightly different design from a Montego/Metro/Land Rover. Same slide-in attachment to the actual column, same plug 12 pins connection to column loom, same Lucas 217SA part number... but... this one runs power TO the lighting where the 827 earths power FROM the lighting. And, no, of course its not a simple as just reversing the wires!! A trip to the nearest big library and a trawl through various Austin Rover Haynes manuals turned up an excellent pin-out wiring diagram for the "new" stalk, so onward and upward!
Not wanting to just rewire all 12 connectors and ignore the nice Vortex loom wiring, I've added 1 relay to provide power (both ignition switched and permanent) to the column stalk and replaced the 5pin main/dip relay with two separate 4pin ones for dip and main. The new switch has positive click to main beam and click into dip beam positions with pullback for headlamd flash on mainbeam. The old "change over" relay (actually it's a small electronic circuit not a relay at all!) is no longer needed. In any event it's a hard to find item if it fails, so good riddance! The place where the changeover unit was situated now has the new relay powering the column stalk.
Only problem at the minute is sourcing the female pins that go in the column loom to main loom connectors to tidy it all up. These are where there are two white multi-pin connectors on the column with male pins and similarly two female multi-pin connectors on the main loom. Pins are probably 2 to 2.5 mm wide. I'm guessing they're probably Lucas but so far a lot of internet searching has turned up nothing. My dear wife suggested Halfords... grrr !!
I've sent Chris G-S a mail asking if the electrician can steer me towards a dozen of them and wait to hear back. Maybe someone on this board has some ideas in the meantime?