I cut a slot just a tad bigger than the Voltwatch LED viewing area in the side of the fuselage (opposite side of the engine exhaust). I then painted it black where the bare wood showed, put a length of clear monocoat over the slot, then mounted the VW inside with the LED's facing out (of course.. ) and held it in place with Blenderm. Works fine.

You may wish to get a tad more fancy, but it is not something that someone would pick out as being out of place. I took the effort to make the cuts straight and to match up with the trim lines of the fuselage. Then I made sure that if there any rough edges, I either sanded them smooth or filled them in with some filler like spackle, then sanded it smooth. I then painted it flat black so it didn't glare. Looks good and the VW is clearly visible to me because I know it's there, but to the casual looker, it's hardly noticeable.

CGr.