This is an Australian Naval Cap. However, the cap tie that was found with this cap is from the ARA General Belgrano - an Argentine Navy light cruiser ship in service from 1951 until 1982.
After almost 31 years of service, she was sunk on 2 May, 1982 during the Falklands War by the Royal Navy submarine Conqueror with the loss of 323 lives. Losses from the General Belgrano totalled just over half of the Argentine military deaths in the war. More information about the Belgrano can be read online.
Inside the cap has the name Delfy's written inside.
measures: 26cm x 23cm x 8cm