Here's some photos of screen inserts made for old style 1953 GM 4104. Two different patterns one for front slider one for rear slider - fit all large sliders. Nylon screen sandwiched & glued into two pieces or 1/8" hardboard (Masonite) & cut to shape to fit into large perimeter frame then slider closes to screen insert. These were homemade 30 years ago & have served us well - no bugs!