I think you got sound advice on constructing  false walls for covering
the signs of technology, architectural changes and craftpersons
signatures.

Another solution would be to cover (stretch over) the specific areas
with Mylar attached to non-critical areas (floating over the area of
interest) at the edges, and then apply the fabric over that covering.
But, you will need institutional memory to know that something of great
significance is below this less obvious *restoration* method.

Flour paste is different than starch paste.  Flour was a traditional
method for hanging wall coverings.  I'm not sure you could rip a
covering of a wall with no damage; this could be in comparison to some
other method popular at the time.  Paper Conservators use the much
stronger, but permanently reversible, starch paste for their
treatments.  Starch paste has the gluten removed.  That's the brown
protein material in flour.

Methyl cellulose has also been used as a wall covering adhesive, but
there are many varieties out there.  It is said to be less attractive to
vermin and this generally true.  The problem with "methyl cellulose" are
the side chains and additives in commercial materials.  Soluble
cellulose with side chains other than methyl groups are generically
called cellulose ethers.  The only truly stable material, for my money,
is cellulose with only methyl groups: methyl cellulose.  This is
purchased as *methyl cellulose* through the standard Conservation or
Chemical Supply houses.

For a recommendation on an Architectural Preservation Professional in
you area contact AIC.  To learn how to select a Conservator and obtain a
referral try URL: <http://palimpsest.stanford.edu/aic/>.

Timothy Vitale
Paper and Photograph Conservator
& Preservation Consultant
Aptos & Felton, CA