It is always interesting to see what you can find at the local hobby shop when you have a specific problem in mind, to wit I stumbled across brass thin-wall tube, 1 mm OD, wall thickness 0.225 mm, item #9830 from K&S Precision Metals, package of 4 pieces, 12" long each, for $4.39 plus tax, so there is plenty of material to screw up with and it doesn't require waiting three and a half weeks and paying $20 worth of shipping from the US.
The OD works out to 0.039", which will fit nicely in the 0.047" spark plug holes and mimic a 0.945" diameter spark plug -- a bit big but I am guessing no one will notice because it will be impossible to get a micrometer in there to verify. ID is 0.022", perhaps a slightly sloppy fit for the 0.016" wire but hey, you can't have everything. I'll just need to fill them up with gap-filling CA and slap on some black paint to mimic the plug wire end. And all this with no drilling! The #78 bit is fragile and I wasn't looking forward to have to drill into the ends of 12 pieces of 3/64" rod.
No further activity until the weekend, I am afraid, I was just excited about the find and thought I would pass it along.