Lead in graveyards

I am writing a condition survey of a graveyard, hoping that it will
lead to conservation work. Many gravestones have lead letters held
loosely by small bumps into the holes in the marble. Many letters
have been lost, some are collected or are peeling, can people
recommend a marble to lead adhesive?

Some marbles have been stained red by the creation of lead oxide,
does anyone have a similar experience, and have you removed it with
a chelate?

Paul Harrison
Phoenix Conservation, Hong Kong


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                  Conservation DistList Instance 19:4
                  Distributed: Wednesday, July 6, 2005
                        Message Id: cdl-19-4-018
                                  ***