The ornamental design for the book binding alignment plate, as shown and described.
FIG. 1 is a front view of the book binding alignment plate according to the present invention;
FIG. 2 is a back view of the book binding alignment plate;
FIG. 3 is a top view of the book binding alignment plate;
FIG. 4 is a bottom view of the book binding alignment plate;
FIG. 5 is a right side view of the book binding alignment plate;
FIG. 6 is a left side view of the book binding alignment plate; and,
FIG. 7 is a front-right side perspective view of the book binding alignment plate of the present invention.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.