Fabricated a small mouning bracket for the ELT control with a couple of nutplates (#6 screws) behind the panel. The ELT plastic control has a rectangular shape and I cut a hacksaw kerf in the outboard vertical sides to slip into this bracket. The screws will pull it flush behind a rectangular hole cut to reveal the ELT.
Had a visitor (RV-6 hangar neighbor) and discussed the status of the project, including his experience with a flying plane.