Bronze screen??

[JIMRPT@aol.com]

List;
  I am in the process of tearing down a Steinway 'A' for rebuild and have run
across something I have never seen before.
In the top two sections of the treble there are individual note bearing bars
that set on the plate between the pins and the Capo, that is not unusual.
However under each of these sets of bars are sections of what appears to be
 'bronze screen' cut to fit under each section of bars. QUESTION: what is the
purpose of these screen sections ?
  I can think of two possible, i.e. 1. to provide a solid foundation for each
section while providing a 'vibration break' due to the composition of the
bronze. 2. to provide a better glue surface to plate and bar section.  These
answers are pure speculation on my part as I don't have the foggiest notion
of what they really are for.
  Each of the sections are in great shape and will be cleaned up and
reinstalled in the course of the rebuild.
  Any other ideas, guesses, or correct answers ?
 Jim Bryant (FL)