I’m no expert but I’m assuming that the frame is aluminum and the bracket is stainless. Not good welding partners. If you’re going to weld up the frame The glass is coming out anyway. FWIW you might...
I think the windshield glass goes into the bottom of that extrusion/ rail. Depending on how high the glass goes into the rail, if there’s enough room above the glass you could put a nut up in there...
Can you remove the frame from the glass? If so, go with Steve’s pop rivet idea and put a back up strip inside of the rail. This will give you fresh holes for the rivets and will spread out the load...
Been using plexus for a while on the boat windscreens. Learned about it from Lexan windshields on roundy round cars. I'll try it out this weekend. Thanks for the info Steve.