To add to Kristin’s excellent suggestions: If you haven’t unframed them yet, photograph them thoroughly front and back and note any markings on the frames. Have the frames evaluated separately; if the frames are old enough, they could have some value (historical or monetary) on their own. The framing has become part of the history of these pieces and unfortunately may have lead to some damage. It sounds like unframing is necessary for preservation, but make sure and document the framing.
