Revolutionary War British 3rd Guards Pewter Coat button

Revolutionary War  period British 3rd Foot Guards  button. Identical to Troiani , "Insignia of Independence " B3G.c. page 35. 22mm in diameter.  Shows light wear and ground action on the face, lacking the iron shank . Dark goldish black patina indicates an underwater find most likely. As part of the famed "Brigade of Guards" they  had a superb battle record fighting at  Long Island, Brandywine, Monmouth, Camden, Guilford Court House and Yorktown.  Ex. Troiani Collection