I would drill holes in the backboard of the case for the air tights and then line it with felt. fold the felt around & staple the felt to the back. Don't use glue on the felt. You should also use tenon joints for stability. Be sure to stain your wood before you join them together, otherwise the glue will not stain the same. I'm putting together either an end stand or a hanging display case (haven't decided which one) with my birth year to include coins & bills


















