This plugboard has white lettering and numbering printed on the plugwire insertion side. At each end two metal nails hold the wooden face in place. The reverse side is covered with male interfaces.
Manufacturer
International Business Machines Corporation (IBM)
Identifying Numbers
Model number
901
Inlaid on the top edge of the plugboard
Other number
30
Handwritten on the white sticker on the bottom edge. The Zero in 30 is quite dark, while the 3 is faint.