[MRM]

There really isn't anything you can to do clean them in any way shape or form that won't degrade the coin and reduce the value. Literally anything you do to them will cause wear. Rinse them off, but that's it. Don't even rub them with your fingers. Paper scratches, so don't use a paper towel to dry. Use a clean cotton cloth, and don't rub when drying, either. A professional might be able to do something with them, but that's best left in their hands.

I can't help on the value. Sound like great keepsakes, though. Were they from an ancestor who brought them back from WWI?