The shelter was to replace a laminated plastic/bubble wrap/space blanket sheet that was draped over the mount to protect it from the elements. The permanent replacement had to be light, easily moveable, and secure against all weather.
To do this, 1/4" mahogany sub flooring plywood was chosen, a bargain at $19 per sheet. To keep it light, few screws or nails were used, and instead 1/2" x 3/4" gluing strips were cut from 1 x 3" spruce boards. This picture shows the basic construction.