Punched on the underside, back edge next to a wall bracket
overall: 2 1/2 in x 21 in x 11 1/2 in
The artifact is a frmed metal shelf with two welded-on wall mount brackets, 12 inches apart. There are the remains of a masking tape label that appears to have said 'DONE'. Three six-digit, illegible inspector stamps are on back edge, near the punch mark.