The first Bricklin meet I attended was an OBO (Organization of Bricklin Owners) event that took place October 19-21, 1984 in Columbus, Ohio.  These plaques were given to all in attendance.

Metal plaque itself is 2¾" (7 cm) square mounted on wood roughly 3½" (8.9 cm) square.  ¾" (2 cm) thick.  Very off center.  Lines up about as well as my car doors.