Yesterday Bruce Clark asked for an adhesive which would adhere reliably
to metal.  He was correct in suggesting shellac, which after all these
years, remains the only thing I know of that sticks firmly to metal.
But there is a trick to using it for large area joints that are hard
to dry.

Clean the back side of the metal piece, and apply a fairly thick coat
of shellac, right from the can.  After a few seconds, when it starts
to get tacky, stick on a piece of thin, absorbent paper; newspaper
works fine.

When fully dry, the paper can be trimmed, and the paper-backed metal
can be installed with hot glue, or any other adhesive that will stick
to paper and wood.

This came to my attention, studying Aeolian 58-note organ rolls.
For a brief period, those rolls were spooled on a tin plated, all metal
spool.  How to stick the end of the roll to the shaft, in the days
before there was Scotch tape?

I found that they stuck a square of paper to the metal shaft with
shellac; then the roll end was glued to the paper piece, the same way
roll ends were glued to the more usual wooden or cardboard cores.

By the way, I have always thought that the tempo slide plates in
Ampicos were eisenglass, not Celluloid.  Celluloid lasts pretty much
forever, for example, reed organ key covers.  But these Ampico slide
plates are almost always found to be warped and shrunken.

Nowadays the term eisenglass often is used for transparent mica, such
as the windows in stoves.  But traditionally, eisenglass was a
transparent plastic-like material, consisting of a very pure, hard form
of gelatin.  Quoting from the internet:

  "eisenglass (ichthyocoll) A semi-transparent whitish substance
  consisting of a very pure form of gelatin, produced from the sounds
  (swimming bladders) of the sturgeon (Acipenser huso, and other
  species of Acipenser), found in the Caspian and Black Seas...
  [it] contains about 80% collagen...  Its use in recent years has
  greatly diminished, due to the rise in use of synthetic materials ...
  The "Surrey with the Fringe on Top"  had eisenglass curtains you
  could roll right down..."

In earlier days, many items now made out of plastic were eisenglass,
but being a hygroscopic organic, they would be bound to shrink and
swell, and gradually loose their original shape.

Richard Vance