Lots accomplished today...
Painted the headers and extension... VHT Hi-Temp Header Paint, flat black.
my "paint booth"

Pre-paint

Primer

Final coat of black

In between coats I managed to get my Lucas tail light installed...

and also cut the flat spot into the upper clamp spacers. Measured, from the fork tube to the outer edge of the "doughnut hole", is 12/32" or 9.525mm. The washer I had sticks out a little bit, but no matter!
I also tidied up the front end wiring with some zip-ties, as I don't want to cut/recrimp a bunch of connections for shorter wires, especially where I already have a basket case and may get some model-correct switches at some point.