I handmade parts that looked a bit like Lenix had, but I actually removed the windshield and removed about 1/3 of the cowl top panel. I chose the shortest area to cut through the top panel as I would be butt welding it back together and wanted a small area to have to repair. I removed the top so I had good access to the bottom panel/hat and could treat the repaired area, seam seal it from the top, and paint it before putting the top panel back on. I really didn’t want to have to weld upside down, so this worked for me. I have lots of pictures, but I would have to dig to find them. My car needed a new windshield anyway (old one cracked) so it was a non-issue. The repair when complete is completely invisible and will definitely outlast me.
My son and I are planning on prepping for paint in December, then I have to get booth time arranged at work. The hardest part, picking a color.