1948 U.K Half Penny

Ok.    Can anybody tell if this is environmental damage or minting etc damage.   (I personally think it’s a lovely looking coin) also, will this continue over all the coin?  Much appreciated.

Something agressive dropped on the coin and took away the patina.

 Maybe someone liked the ship design, and glued the other 

side so it could be stuck on a board for display purposes. 

It is lovely, so a possibility.  Thank you