Back in the late '60s I remember seeing a unit
from IBM that used film
storage. The film was a small rectangle, maybe 1" x 2-1/2". These were
stored in magazines of some sort, IIRC. ... does this ring a bell with
anyone?
One of those cubes was shown to me by an IBM research staffer in 1991,
he knew I was interested in computer history and arranged for me to get a
tour of the hardware archive center. The cube matched your description
quite closely, I remember it now (somewhat weakly) as being like safety
razor dispenser.
John A.