I'm surprised you haven't been able to find used lenses or even modern replacements. It seems like lots of vehicles used those fender lights for decades - school buses, dump trucks, etc.
This forum is a better car club than most "real" car clubs in my opinion. I've been around here for about 4 years and have gotten more useful help and advice than I've gotten from the Cadillac and LaSalle Club in 18 years.