The site http://www2.netdoor.com/~rlang/ contains information on
building a MIDI controlled Xylophone and a MIDI controlled Harpsichord.
There is also information on the restorations of an 1840 square piano
and a 1920 Marxophone.

I have received good feedback on the electronic circuitry which has
been applied by readers to theatre pipe organs and calliope.

Bob Lang