Well, this took longer than expected. Removed protective plastic and positioned and cleco'd after adding cork strip. Discovered, the trailing edge was too long and raised the canopy too far on the trailing edge and the screws did not reach the interior. Removed the canopy and trimmed about 1/3" from the trailing edge and repositioned. Getting the screws tightened without a helper was complicated, but I eventually figured out that I could use a large spring clamp to clamp a large adjustable wrench vertically to the interior to hold the nut while I tightened the screw from the outside. Riveted the sides of the canopy with the aluminum rivets provided for the back windows.
Inside view
Outside View - LED fixture for temporary interior illumination