The Ed Link Jr. interview recording mentioned in 170215 MMDigest has
Mr. Link mentioning running an airplane that had a "Spaulding's Bread"
piano-roll style scrolling light advertising display on the bottom of
the aircraft wings.

Here is the mechanism in "Modern Mechanix" March 1934.   Note the
nixie-tube style matrix design.

http://blog.modernmechanix.com/player-piano-roll-controls-sky-sign-tiny-ford-has-10-horsepower/

Karl Ellison
Salem, Massachusetts