Bent prints--help!

I thoughtlessly turned a box of b/w prints on its side about a week ago. Now I find that the prints scrunched down to the bottom and are bent--curled rather than truly bent, luckily.

These prints are 20-years old, on pre-resin-based paper, and are of real sentimental value.

How best to flatten them safely?

You might try gently wetting the back of a print with a damp rag, then pressing between double thicknesses of blotter paper under a couple of books and let dry over night. If you try soaking the whole print, you might remove any spotting or touching up.

Or you could just lay them down flat and be patient. They will flatten out eventually.

The first thing I would try, before taking any other more serious measures such as rewetting them, would be to place them between pieces of mount board and press them. A dry mount press would be ideal, but you can try books as well. I've had luck with both. Better yet, just dry mount and overmat them.

One clarification - you say "pre-resin-based paper", but early versions of RC were around easily by the mid 70s, longer ago than 20 years.
Do you mean that these are RC paper, but earlier versions of what we have today, or are they fiber paper?