Many thanks, Brian, both for the quality of the information and for the speedy reply. Much appreciated I believe that MTB 457 did survive the war to become converted to Radio Controlled Target Boat P8201.
I'm trying to research my dad's RN service, especially in Coastal Forces March, 1944 to June 1945. He also served in HMS Euryalus April to December, 1943. Any information gratefully received.