Scan each photo and upload it to the AI Picture Restorer on Hotpot.ai:
https://hotpot.ai/restore-picture
It's an amazing tool!
(Note: Don't be deterred by the reference to 'credits' on that page. While several of the services offered by Hotpot.ai do require users to purchase credits, the basic photo restoration service is a freebie).
Alternatively, scan the images and email them to someone who uses Photoshop or GIMP. It should be possible for them to return the pictures to close to (or even better than) their original state. If you'd like me to do it for you, just let me know and I'll provide an email address).