Approx. size is 1 and 3/4 inches high by 1 and 3/4 inches across.
Unlisted in most reference books but see "A Source of Pride" pg. 31 and Appendixes, pg. 141 refers to this badge, sold at Jeffrey Hoare Auctions in 1998 and subsequently present in the Doug Buhler collection.
Extremely scarce, only listed in Brooker's CEF Book under 30-6-11-206 (as a Prototype).