Silicon caulk

I am in the process of deinstalling exhibits that were built in
circa 1968. Some of the artifacts were mounted on plexiglass shelves
with clear silicon caulk.  These are stuck fast and are tight enough
to prevent a razor blade from slicing through the caulk.  Does
anyone have any good suggestions about the least damaging method
separating of artifacts from their mounts or is this something best
tried by a professional?

Alan Hawk, Historical Collections Manager
National Museum of Health and Medicine
Armed Forces Institute of Pathology



                                  ***
                  Conservation DistList Instance 14:33
                 Distributed: Monday, December 18, 2000
                       Message Id: cdl-14-33-021
                                  ***