Vent: In my experience, waiting for a custom lintel to arrive took so long we built a temporary arch out of scrap wood. | Bricklayers - Pinecone Attack
Wait, what? A plywood shed door held on for fifteen years without a proper hinge? That's insane. I've seen metal gates fall apart in half that time just from rust. Plywood usually warps if it gets damp, let alone lasts a decade and a half. Your uncle must have had some magical shed or something.