I allowed myself a slightly different b/w edit - just to give an idea.
I used content aware fill and some other PS magic to correct empty spaces after the perspective correction.
Tones are not completely perfect, but it gives the idea.
After seeing your and my edit(s) I think we start getting an idea why you had doubts trashing it.
Cheers
~Chris
Hi Chris,
Thanks for the attempt, but I don't think you had enough information in my attached jpeg to do the best job with context aware. However, you've given me an idea. The texture on the door on the left at least adds a bit of interest to the image, so I've expanded it with context aware fill, a bit of selection/copy & paste, and some work with the healing brush.
I don't think I've ever worked on such a bad image before. The detail in the shadows is virtually non-existent.
If I decide to buy a kit for wet scanning, this slide will be a good test. The attached new version, scanned on my Epson V700 flatbed, is about the best I can do.
Cheers!