Hi Jim
Are you able to just scan the one photo at 300dpi?
There isn't very much to work with and if you scan just the one area, we might be able to get a clearer image as there is detail in the photo.
I've had a quick play and added texture which I don't like doing, but it's a quick fix and a bit of cheat as it hides flaws, but I'm sure we can get a better result if you can give us a better scan.
Kind regards
Caz