Are they not the mod plates form the cockpit section that was at Caernarfon?
From post #19 on here, http://forum.keypublishing.co.uk/showthread.php?t=115754.
F8 is the correct number for Gannet however the 20134 serial number doesn’t fit in with the known Gannet serial numbers that I have listed, the final AEW (and highest of any Fairey c/n) being 9516.
My only guess is that either it was from one of the Indonesian sections that were swapped around or a ground trainer – but that doesn’t explain how it ended up with a pretty full tally of service mod plates.