I made on for my '70 from aluminum sheet 1/8" thick
I cut and bent it to conform to the contour of the windshield frame and to use the existing mounting holes for the top.
I bought some sewable plastic "J" channel and had my buddy at his upholstery shop sew it to bikini top that I had bought from someone on face book.
It isn't exactly like I want it yet but I bought some more material to make another one this spring.
Here are a couple of pictures of the header I made from aluminum.
the tabs on the back are bent down to catch the mounting holes in the windshield frame
top is loosely fitted here
