I'm just guessing, but I would imagine that your Duvall is a bronze casting made by Dave York (Past-Tech) in Vancouver B.C. under contract to Speedway Motors. Being a casting it may be difficult to straighten out, but there may be someone on here that could help you out.

Dave's castings are top notch, and you can buy the complete windshield from Speedway, but they ain't cheap. ($1700.00)

mick