Sheet Metal for 1966 Plymouth Valiant 100

I'm not sure if this is a common problem with these cars or if it's unique to my specific car, but halfway down the fender on the top next to the fender/hood gap there was a small patch (about the size of a half dollar) that almost looks like water had collected there? It's hard for me to explain from memory but I was told that the best thing to do would be to replace the fenders. Any thoughts?
Small holes can be patched. I would suggest you get the car and check out the damage before you pull the trigger on repair parts. Pieces are around. If you don't have the tools in the know how to do the repairs then you'll have to find someone that does body and Sheet Metal work that can get it done for you.