My 1999 22' Cruiser had one center window top hinge support break, and the aluminum piece that supports the nylon rod fell overboard. I called DSG, and they wanted over $700 for a new window w/shipping. I took the window out (not easy) using putty knives, piano wire, and a lot of leverage. The hinge was held in place by a set screw, not welded. I had a new aluminum piece fabricated locally by a machine shop, replaced the screws on both sides, painted, and reinstalled the window. Cost about $50. The window broke because of the pounding the boat takes, and the leverage on the support when it is fully opened. I have a single support on the starbord side of the window.
While not the same problem that you have, my suggestion would be to remove the window, get the broken weld rewelded, replace the window in the boat, and then keep the opening window partially closed when running hard to keep the leverage down. You still get plenty of air flow, and can open fully when stopped or going slower. Works for me!
Dun