DANG!!!
It's the little foxes that spoil the vinyards, biting me in the butt!
Got the ignition rotor sorted, the bike fired up, sputtered and wouldn't fire again. Then it occurred to me - I hadn't tested the alternator rotor! I took 2 thick washers and sandwiched the rotor in my vice, then took a large pair of channel-lock pliers and was easily able to rotate the bloody thing almost 90 degrees.
Didn't take long to sort through another 2 rotors to find one that definitely wouldn't budge. Spiffed it up and mounted it, re-checked the timing and it was very close. Pure coincidence. I adjusted the ignition stator to spot-on static time and nipped everything up.
The last two nights, it's taken me a long time to fall asleep while thinking about all the details that could be contributing to the bike not wanting to fire right up. Then it occurred to me that I hadn't checked the needle specs on the carbs. Sure enough, they were 2-indent needles for Triumph, not 4-indent needles for Norton 850. Also, the spray tubes are standard Triumph profile, not the cut-away Norton profile.
After digging for an hour through all my carb stuff, I found a nice boxed matching pair of 932s with modern slides of the proper 3-1/2 cutaway, although the jets and needles were incorrect. A bit more time pulling apart my 3 other spare pairs of carbs and I found a SINGLE 4-indent needle. AAARRRRGH! Picked up the phone and got a new pair of proper needles on the way.
Meanwhile, I'm seeing that the difference in a 2-indent and 4-indent is such that I can go ahead and install the 4-indent in one carb, on it's middle clip groove, and the 2-indent needle on it's top groove in the other carb, and they'll be very close (2-indent needle will be as lean as it can go).
Yellow dots indicate the identification indents , green lines indicate the clip setting grooves, red lines indicate the two grooves that will allow "close match" settings (I intend to use the upper close match, as the lower close match is relatively farther apart)