I positioned the two aluminum angles on the map box flush with the back side. Use three clamps on each to hold them in place. Mark five rivet holes on each side, punch the locations and drill the ten #40 rivet holes and cleco the pieces together as I drilled the holes. Take everything apart and deburr. Reinstall the clecos. It came out really good. Tomorrow I will see if cutting in the angles for the sides make any sense, or just use the separate backing plate bent along the sides.
