Makes more sense if the kit was Fleet Air Arm than RAF. Out of intrest, is there any flotation built into the jacket? This is a trade mark of Beaufort kit. One thing for sure, it is and always has been ******* expensive! Mind you if you think your life is cheap, buy cheap kit. The obvious that comes to mind is SBS or RM Commando use.
http://www.rfdbeaufortmarine.com/