I think the answer for adding a xylophone to a piano was answered well.
I personally do not care for the reiterating xylophone and prefer the
single stroke xylophone on A rolls.  Most of the A rolls play just fine
with a single stroke xylophone.

The number of notes on original instruments was inconsistent, with some
instruments having 22 notes ending three notes short of the top note,
while others had 25 notes covering the top two octaves in the piano.
Some of the original pianos with pipes had more pipes.

I do not think that A roll arrangers paid much attention to the added
instrument or how many notes as compared to the O roll (Coinola).  In
the Coinola it is critical that there be 24 notes on the xylophone.

Robbie commented:

>[ Most A-rolls seem to me to play one half-step higher than the
>[ standard key in which orchestras played the tune.

A rolls do not always play the piano a half step up or down.  It
depends more on the piano than on the roll.  For example, a Seeburg K
versus a Seeburg E: the Seeburg E plays the A roll in the correct key,
the Seeburg K does not.

Dave Ramey also sells recut A rolls if anyone is interested.  He just
got another cutting done and I think he sells them for $35.00 each.
Also Rob DeLand (BluesTone) has one recut A roll for sale that should
be in every collector's collection.

Don Teach