57 windshield

[ezernut9mm]

hey guys, i need some serious help here with a windshield install. my bro has a 57 cab with the original windshield. after a few years of sitting in his basement we finally got around to getting the truck up and running. so far so good. now, the original windshield-that came out of that cab, will not reinstall correctly back into the cab. we have tried two different gaskets (one from chevy duty and one from jim carter) and we still cannot get a seal at the top right corner. we even had a friend come over that has a 57 and help us install the glass. he's an older guy that has a lot of experience with this stuff and can't figure it out.
i was hoping someone could give some advice or something. i don't know what to do now, and my bud-that owns the truck is ready to throw a match to it and i don't want that. (maybe i can buy it cheap now. lol)
anyone ever run across something like this? help!