I built a xylophone for my O-roll orchestrion, somewhat a copy of
the Wurlitzer, but with a modification: I added dampers since my tone
bars were more like bells and had a long sustained tone.  Therefore,
two pneumatics per bar.  I would be happy to send you the "plans"
I drew up.

For the strikers, I used small wooden balls of about 3/4" (available
from Hobby Lobby) mounted on the end of grand piano damper rods.  These
have just the right amount of spring to them and they look a lot better
than hacksaw blades.  I adjusted the balls about 1/8"-1/4" shy of
hitting the tone bars when the pneumatics are closed.  This seems to
work well.  Of course, some fine adjustment is needed to make sure that
all strike fairly evenly.

Good luck.

Jim Quashnock