Page One: the consignment book
Nudge. Four shelves, and a seven. The number cannot be a place in the office. Look at what else sits on each line, and count.
Harder
Count into the consignee's name. The second letter of KRAMER, the third of HEIDRICH, and so on down.
The answer
The word is riverbed.
Each shelf number is a position in the name beside it: KRAMER 2 is R, HEIDRICH 3 is I, SILVESTER 4 is V, BRAUNFELS 7 is E, OSTERMANN 5 is R, HOLZBAUER 5 is B, NEUMANN 2 is E, WEIDMANN 4 is D. Read down, and the clerk has written RIVERBED, which is what the line runs along for three quarters of its length and what he meant by it is the next question.