You need some pretty strong strap hinges, it would seem. You might try
www.fpmarine.com, he has a lot of odd stuff as surplus. Most of it is new stuff, or blems, purchased in lots from boat builders.
1975 32' Flybridge Sedan, twin Perkins 6-354 diesels, 1:1.53 velvetdrives, 16 X 19 props. Merritt Island, Florida