Wet photographs

A conservator who isn't on the DistList has asked me how to deal
with a group of resin-based photographic prints in mylar envelopes.
They got wet some time ago and have since grown some (not a whole
lot) of mould; they're still wet, and she is keeping them in the
fridge while she works out whether and how they can be dealt with. I
have no particular expertise here, so I feel I should open it to the
rest of you.

The original negatives still exist, and I believe they can be used
to make new copies; but is there a way to salvage the originals? She
can't get the gelatine to separate from the mylar, and (needless to
say) doesn't want to lose more of the image than has been lost
already. She knows immersion doesn't work.  She has thought of
freezing them, in the hope that this would make the gelatine and
paper more rigid than the plastic and allow her to remove the mylar,
but she'd like to know if someone else has done this before she
tries it.

I have read the items in the DistList on separating photographs from
glass, but haven't been able to find anything on separating them
from mylar. Both suggestions or pointers to other sources would be
welcome; on my part, I'm now going off to peruse Topics in
Photographic Preservation.

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                  Conservation DistList Instance 13:21
               Distributed: Thursday, September 23, 1999
                       Message Id: cdl-13-21-020
                                  ***