Thanks to JamesW who told me about PB Blaster. Nothing else worked on that last front valance bolt. The housing on the left turn signal was gone. This is the one on the right, and a shot of the old and new turn signal housing. When I started working on it the turn signals actually fell out when I pushed on them. The only thing holding them in was the rust. I ordered two New Old Stock turn signal assemblies from John's Mustang...the housings are courtesy of the previous owner who had not yet put them in...and the lenses are OK to reuse. The valance is actually in beautiful condition. No rust at all front or back. One turn signal opening in the valance has lost just atiny bit ofmetal to rust from the turn signal assembly, but not so much as to be a problem. I went with New Old Stock ($45 each side) because the car is pretty much original and I wanted to try to keep anything visible as original as possible.