Yeah, t-molding is bent until it's installed. The process of installing it flattens it out. You would need a flat surface to hold the glue. Plus t-molding gets very bumpy if it's not installed on a perfectly flat surface. Trying to glue it to something would cause bumps.
Also, I've seen aluminum tape used for sealing duct work, and it'll definitely work for a while. My only concern there is that it'll dent and tear fairly easily. It's basically like thick, adhesive backed aluminum foil. Realistically, even the aluminum railing I mentioned would be difficult to work with. Aluminum is soft and prone to scratches and dents at any thickness.
I think the auto body chrome plastic modling sounds like a great idea. You mean like the stuff used for door bumpers, BobA? I don't know if they make it 3/4" thick, but that should almost definitely work if they do.