Just a quick note on the subject of Keys that won't move:  I had an
Autopiano (my first "restoration") that the keys didn't move and it did
have a keyboard lock lever.  The keys all moved freely, but the balance
was in such a way to keep them down.  I left it that way with
inexperience as my reason.

Later I had an English foot-pumped Duo-Art (half-Duo-Art).  The keys
didn't move there either; I believe that it was the way it was supposed
to be.  That was a beautiful little upright -- too bad it wouldn't stay
in tune!

Finally, in the other collection here in Israel there is a Mason &
Hamlin Red Welte.  They have a pneumatically operated key-lock that
operates whenever it's playing.  If you push down and hold any note,
it allows all of the keys to move.  I assume that it was to keep them
silent, but it really irritates the owner.

Eliyahu Shahar