I wound up using this to help seal my door.
Still working good after +6 months. Look around at the different types of gaskets he offers - I chose the self adhesive technical felt, but there are other options. Wish I had put straps on the inside like your mockup so the gasket would seat better. I still might add some like you have it.
Weber 26.75 OTG w/CI grates & SJ/WSM Mini
Home built 24"x72" reverse flow stick burner trailer with 18"x40" grill w/CI grates and upright SS gas oven/smoker.
Home built 48" fire pit with a 30"x30" Santa Maria style ranch grill.
Home built lump charcoal retort, iGrill & a bunch of other cooking toys.