Anyone have a rear window or advice for repairing the fixed aluminum rear window on my 68 Shasta Compact? It is covered with multiple layers of silicone and other sealant, came apart at the corners when I took it out, and had part of the lower lip cut away by the PO when they installed a window A/C unit on one side. I'd ideally like a replacement fixed glass window in good condition, or at least suggestions on cleaning up the existing frame and joining the corners back together. They look like they were glued together with something gray like JB Weld. Thanks!