I trimmed the formed plexiglas, and drilled the mounting holes, and dimpled the metal and countersunk the plexiglas. Only one good thing about 107 deg days; you don't need a plexiglas drill bit! I'm going to use #6 flush screws, and drilled the plexiglas with 3/8 in holes, counter sunk on top. I put the plexiglas in the house, wrapped in some pillow cases and I'll set the aluminum aside for alodining and priming later. I'll install the plexiglas after putting the fabric on by burning a small hole in the fabric over the screw holes and bolting the plexiglas and frames in place with some RTV as sealer before the final paint is applied.