Ventured out to the garage with a recharged electric drill and made some "commitments"...

The round, 3" DOT legal tail light.  I think I will refinish the chrome ring/bezel in black.  You can see the issue with the tail section -- I've measured it many times, and it's not so much a twist, as a flaw in the original mould -- the LHS of the tail (in this pic) is "taller" than the right.  When the subframe is all welded up, some strategic application of heat might allow me to twist things a bit to compensate.

I decided to go with the DOT approve 4.25" headlight I am using with the xt supermono cafe racer.  I broke out the big hole saw and did some cutting.  The headlight will have to stick "out" from the fairing somewhat (typical of most endurance bikes) but it will be frenched in somewhat.  The used food container gives a sense of what it will look like.