I have a 1924 Marshall and Wendell Ampico A upright which was restored
some twenty years ago.  The tubing in the lower action (expression
system) has now perished and needs replacement.  Some of the tubes are
labeled as follows:

    The 1B, 1T, 5B and 5T tubes (where they go onto the crescendo
    pneumatics) are labeled with pink celluloid or plastic open-ring
    labels with black letters in a neat (Helvetica or similar) font.
    One (only) such label is also on the tubes of the upper action
    where they are removable at the left-hand and right-hand ends of
    the action.

    All the other small-bore tubes at the left-hand and right-hand ends
    of the upper action are labeled with stamped metal rings (which
    are quite hard to read).

I have wondered whether either of these types are based on identifi-
cation rings for birds.

My questions are:

    1. Are either of the above forms of label original or were they
       added later?
    2. Are suitable labels available anywhere?
    3. What do people recommend for labeling tubes? (Other than
       obvious solutions such as writing on masking tape labels etc.)

Many thanks for your comments and answers.

Arthur Jones
From the Midlands of England, having escaped the worst of the snow!