Ink stains on limestone

I have been asked to remove red ink stains made by a self inking
stamp from a limestone fireplace (there are approximately 14 sets of
stains). Methylated spirits and hard cleaning detergent had been
tested prior to my seeing it with little result.  I have tested the
'Gompers Gel' (see JAIC 28, 1989 pp19-20) which has removed some of
the ink but a substantial amount remains.  Does anyone have any
suggestions for its removal? Julian Bickersteth

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                  Conservation DistList Instance 12:48
                 Distributed: Monday, November 30, 1998
                       Message Id: cdl-12-48-016
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