I'm not sure what the host coin for this counterstamp is - it's about 24mm in diameter and a very thick planchet (US cent shown for comparison). One size seems to have been made concave?
From the cut and shear edge shown in last photo I would say that it was not a counter-stamped coin. It looks more like a punched blank that was imprinted on the concave side as it was being punched out of a sheet. Then it was crudely imprinted by hand with the letters BHS on the other side. JMO
