I've tried working on 'birdcage' pianos for customers to save them the
disappointment of having wasted their money, but it's always been a
hopeless undertaking.  The most frustrating and perplexing thing about
them is, how did they ever tune the damn things?  The overdamper wires
obstruct access to the strings so you can't insert a temperament strip
or muting wedges.

One time I removed the bottom board (under the keyboard) and tried
muting the strings from below, but this necessitated bending down and
moving back up hundreds of times in the course of a tuning; very hard
on the back muscles.  Now when I come across one, I regretfully break
the sad news to the customer and walk away from the piano.

Larry Lobel
Virtuoso Piano Service
Petaluma, CA