I decided to fabricate the spacers, that will be used when the fuselage gets installed into the hull. There are a set of 2 spacers, for each of the two three-holed channel brackets, under the main bulkhead.
They are made from UHMW stock, and come in two sizes: 1/8" & 1/4"
I used a "spare" channel bracket as a template, to line up all of the holes on the drill press.