Hello to all,
I share with you another Home Front helmet, it is a Police MK2 N°1 (no-magnetic material), with a nice and uniform time patina.
Outside and inside it is blue painted, the MK1 liner is "J.C.S. & W 1939" marked and is also visible the broad arrow acceptance mark.
The shell is marked "C51" or "G51" ?, but is not visible the manufacturer mark; in my experience I have seen other helmets with similar marks and were produced by BMB, but I'm not sure.