FIG. 1 is a left, front and top perspective view of the coin mailer and display device showing our new design. FIG. 2 is a right, front and top perspective view thereof. FIG. 3 is a front elevation view thereof. FIG. 4 is a back elevation view thereof. FIG. 5 is a top plan view thereof. FIG. 6 is a bottom plan view thereof. FIG. 7 is a left side view thereof; and, FIG. 8 is a right side view thereof.