I might be wrong here, but wouldnt it be possible to find the location of the SSR (if it even exists) by using the freedom of informations act? Does this apply to military installations. I suppose not, as they would be under the official secrets act, but it's worth a shot, especially with the theory of the loco's simply having been sealed inside the storage compound.
I like that theory, as like you said, with the amount of steam enthusiasts in this country it would have been almost impossible to disguise the
scrapped parts of all those locos, no matter how much they cut them up somebody would recognise something, and how would they have ever have
transported that large amount of scrap metal. I for one would have been highly suspicious if I'd seen counts of lorrys appearing from nowhere, near a
small village, and driving off in convoys.
So therefore, I'd like to believe that somewhere, there are hundreds of sleeping steel and iron giants waiting to be rediscovered. If the complex
exists that is!