Portrait on photographic base

The following message from Jenny Ford <gford [at] infoave__net> was sent
to me at ICOMOS. I thought that this list might be the most
appropriate one to answer her. Anyone who can help is welcome to
write directly, to me, or to the list.

    From gford [at] SunBelt__NetFri Aug 09 00:09:12 1996
    Date: 7 Aug 96
    From: Chris <gford [at] sunbelt__net>

    While working on repairing part of our farmhouse, we found many
    objects stuffed into the walls.  We have no written evidence,
    but most indications lead us to believe our house was built
    right at the close of the Civil War.  Among the things we found
    was a rather large portrait of one of my ancestors.  I don't
    believe that it is all that old, but it is still rather
    puzzling.  It looks like a cross between a drawing and a
    photograph.  It is on paper that is glued or fused to canvas or
    some type of fabric.  When we found it, it was covered in soot
    and we had no clue what was underneath it. My mother had a wet
    rag in her hand and just wiped it off revealing the
    picture. She then got the vacuum and got the majority of the
    remaining dirt off.  I am afraid to do anything else to it for
    fear of harming it.  It also has a tear on part of the border
    that was apparently at some point covered by a frame or mat.  If
    you have any ideas about what I should do to take care of this
    picture, please let me know.  I am also curious about any
    insight you might have on the exact type of process that might
    have been used to create the picture. Was drawing on top of a
    photo common?

        **** Moderator's comments: See Ruggles, Mervyn. A Study
        Paper Concerning Oil Paintings on a Photographic Base.
        Preprints of papers presented at the eleventh annual
        meeting, Baltimore, Maryland 25-29 May 1983 (American
        Institute for Conservation, Washington DC)

    If you are unable to help, please forward my letter on to
    anyone else that you think might be of service...or refer me to
    them. Greatly indebted,

    Jenny Ford
    Elmwood, TN

Peter Stott

                                  ***
                  Conservation DistList Instance 10:18
                 Distributed: Tuesday, August 13, 1996
                       Message Id: cdl-10-18-016
                                  ***