I did business with several firms of the old 25MU for many years. I'm no expert, but there were/are a great variety of types of buildings on the site, some of which certainly look like they were intended for munitions storage. They have huge concrete blast-walls with only a narrow slit along the top edge to allow light in. These contrast with the hangar-like general storage buildings.
A relative of mine, Johnny Crayton, used to work there in RAF days and he told me that there used to be a Mosquito on gate-guard duties, but orders came through to destroy it, which the staff reluctantly did, with an earth-mover, and burnt the remains. As with many old aerodromes, there were stories about stuff buried. Many of these are apocryphal, but Johnny was very specific, as I was very sceptical... He related that it used to cause just as much aggro to have too many items as too few, especially expensive things like engines. In this case Merlins.... However, even if it's true, they will be corroded junk by now, there isn't any point in losing sleep over it....!