I'd like to add a note about piano roll cupboards.  I built some roll
cabinets and came across a couple of good tricks that worked very
well.  Regardless of how fancy or plain it's built, there are three
critical dimensions that do the job.

First, the vertical distance from the top of a lower shelf to the
bottom of the shelf above it should be nine inches.  This allows enough
room for a vertical stack of 4 regular small, square roll boxes.  It
turns out that a vertical stack of three small Ampico "high-hat" boxes
is about the same height of four small, square boxes.  This allows the
two types of boxes to be stored side by side on these shelves with
minimal vertical wasted space for either.  A slightly shorter dimension
could be used but a four-high stack of some of the slightly oversized
small, square boxes that a number of recuts are boxed up with may not
fit.  This is also a small enough stack that even a fragile old bottom
box won't be crushed.

Second:  the shelves should have a rear to front dimension of about
an inch shorter than the roll boxes.  This causes the roll boxes to
protrude over the edge far enough for you to get you fingers under the
bottom side of the bottom box.  With fingers on the bottom and top of a
three- or four-high stack, you to easily pull the stack out very little
chance of damaging a fragile old box.  This allow the stacks of roll
to be touching horizontally all the way across any compartment of the
cabinet making very efficient use of space.

There doesn't seem to be any need for vertical partitions accept to
maintain the shelf spacing and making sure the shelves are well enough
supported that they don't sag in the middle due to the weight of the
rolls.  The vertical partitions on my cabinet are about three feet
apart mostly to work with the size doors used for the roll cabinet.

Third:  the shelve thickness should be no less than about 3/4-inch
thick as this is needed to have sufficient room for your fingers.
Be sure to put one of these shallow shelf boards on the bottom board
of the cupboard so you can reach under the bottom row of rolls.

Regards,

Dick Merchant,
Carlsbad, NM