Thanks to several hours, yes hours
of Mike's help on the phone, I managed to trace every significant wire in the ignition circuit. Yanked the dash and everything to get to the wiring.
The end result was that despite checking twice, I thought the main fuses were all fine (visual inspection) when in fact one had blown.
It probably blew as I had a loose connection at the starter...
Again, many,many,many thanks to Mike for his time and patience with me.
Sign me up for the Darwin award!
P.S. Mike and I have decided that the D-90 source needs to add a private jet to next years budget. Mike could have flown down, and would have probably noticed the bad fuse right off the bat, smacked me on the head and then helped me with the original problem