I completely agree with Alpha. I have done my share of free retouching for friends, but this is an utter nightmare. These images are probably recoverable, at least to some extent, but keep in mind that it will be many of hours of tedious work before you can make them look presentable. And if you were to take these to a professional retouch service, you'd be out of a few hundred quid for sure. But hey, if you live for a challenge, go for it, very often these kind of projects are fun, and give you a great feeling of accomplishment once you're done. Start with levels, curves and spotting, but be prepared for some painting as well, digital or otherwise.