Don't ya wish ya could Tom? Naw just emphasizing how much work went into making the first one and make it look, feel and fit like the original one that was in there.
The junk cardboard ones that the vendors are selling are just that, junk material, and made to small to fit the flange and not enough material to make it right. Even if ya can get it hacked in place, I can imagine what the cardboard would look like after a few sessions with nice humid summers. Just ask Wilber who started this thread; “Leaks though the door and window gaskets soon had the cardboard pealing and bubbling. Seemed like a waste of money.”
Like I said, I used weatherproof panel board like you would use for door panels. I got a couple of sheets from Mike Bell's automotive upholstery shop. Could have used the plastic, in fact he suggested I do just that, it sure would have been easier to form but I was trying to keep it original. Sharp bends on the panel board was the biggest challenge. That’s why I had to make up a compression die for the bend lines, that’s the way its done for the folds on cardboard boxes, and it’s the only way I found to keep the board from delaminating when you bend it. Tried heat and soaking with water and various solvents and compression came out the best.
In a few years, after mine has developed some patina I doubt if anyone will be able to tell it from the original one even on close examination and I feel confident that it will still be in one piece.
Maybe there's a niche for you Tom! That is, if ya can mass produce them for a reasonable price and make them so they fit with out having to rework or remake them, and package them with the proper clips/U-nuts and screws.
Denny Graham
Sandwich, IL