The sheet alclad is in! I traced the two indent shape and cut with snips. I belt-sanded the edges to the marked line, and fine-tuned by placing in the wingtip light indent (trial and error). I used my bend brake from the empennage kit build to nail the bend.
With the alclad plates held firmly in place, I marked and drilled to #30 three rivet points on each facet. Then with the plate cleco'd into place, I shot a little marker paint through the nut plates from behind to mark where I should drill their holes through the alclad plate. This allowed me to drill those holes into the alclad plate. It wasn't perfect, but close enough (I enlarged those holes slightly to allow screw alignment, and the imperfection will be hidden by the lights themselves).
Had to be very careful not to scratch the alclad because I want this surface to be nice and shiny.
I'm ready to remove these parts, paint the edges and backing on the fiberglass black, and install the clear lens cover without dinging these parts.