Howdy Shoprat,guess you and I are thinking along the same lines. I went up today during my lunch hour and measured a Bargman L-300. It's a little big,but with some cutting and tinkering, I could make it work. Better to big than to small I think,plus parts are easy to get.
I'm thinking of a whole door also,but i think it also would be hard to find.This one needs rebuilt soooooooo. Problem there is freight if I could find one. I'm in Montana winter coming so guess I'll wait on the Bargman and keep hunting for the right size Keyler or a used door.
Thanks again Shoprat for your input and any other idea's.