The Maestro player action currently on eBay auction is, indeed, a keytop
player, but a very early design primarily for use on organ keyboards.
This accounts for the small number of actuating rods.  With difficulty
I can count around the high forties from the photos so it may play the
46-note roll or not all the notes from a 58-note roll.  A copy of an
advert for this item can be seen on page 267 of Ord-Hume's book, "Barrel
Organ."

The recent posting stating that the arrangement of actuating rods was
not conducive to a keyboard layout misses the fact that the internal
layout of the pneumatics is of primary importance, whereas the position
along the length of the key where the rod operates is arbitrary.  I know
this will give different throws for two pneumatics operating, say,
a white note, but for a device operating an organ keyboard with limited
travel this is of secondary importance.

It is unclear from the eBay photos or the advert in "Barrel Organ"
where the pumping bellows are situated.  Hopefully the purchaser will
tell us.

Nicholas Simons,  Derby,  England.