Stamped in blue on a sticker at the top front of the panel
This incomplete number is loacted on the back of the panel
Printed in white on the front top left corner
overall: 8 1/2 in x 26 in x 11 1/2 in
The object is a metal rack standing on built-in legs. The rack has spaces for 5 vacuum tubes. Besides the tubes, the rack has 16 BNC connectors and another connector (probably a power connector). "D-Bus Driver Arithmetic Rack 9, 12, 10" is handwritten in red on a card taped to the front of the panel.