I want some accordion gasket that is mounted flat on both edges. Not like the typical gasket that slips down on a thin strip of metal or fiberglass. My thought is to frame unit opening I'm mounting with 1 1/2" tubing and do the same with my sleeper and then screw down gasket flange with screws and a cover strip. Anybody ever saw any of this type gasket and if so where can I get some of it. Thanks for yalls input!!!