The lower kickboard is often missing on coin pianos, I guess so that
one can see the mechanism at work.  The originals were made of a core
wood of wormy chestnut, cross-veneered with poplar, and the top (face)
veneer the same as the piano case, with the inner veneer facing the
inside of piano faced with the same veneer as the inside of the piano.

Most old upright pianos have kickboards that are too small for coin
pianos.  The coin piano kickboard covered the entire opening in the
bottom of the case and had a lock that, 99% of the time, was a
Eaton-Yale flat key desk lock.  Coinola used two pieces of metal with
an opening for a padlock on some of their models.

Don Teach