After some research on the name on this Royal Navy clasp knive I found out the probable owner was a Petty Officer and was part of the crew of the Wild Swan which was sunk on the 17th June 1942 by Junkers Ju 88 bombers. He must have been one of the wounded seamen who were rescued but died of his wounds the following day.
HMS Wild Swan (D62) - Wikipedia, the free encyclopedia
CWGC - Casualty Details
Royal Navy casualties, killed and died, June 1942
ALLEN, WILLIAM GEORGE
Date of Death:
H.M.S. Wild Swan
Panel 62, Column 2.
PORTSMOUTH NAVAL MEMORIAL
Son of Henry John and Elizabeth Allen, of St. Helen's, Isle of Wight.