"...is a principle that generally recommends selecting from among competing hypotheses the one that makes the fewest new assumptions."
Or, as we like to say it, 'the simplest explanation is usually the one that works.'
I say it's an original horde/find. I think that while we can try to dissect every element of each picture, the bezel inserts may be old 'trade-ins' that were being parsed out again. Yes, you can paint a "T" on a 5512 or 5513 dial, but look at everything: the vials that the hands are in, the wrapping, the lubes and oils and other bits and pieces.
This is a box of stuff that went to the UK, where these military dial Subs originated. Somebody was assigned to or volunteered to service them, and got a box o' stuff to get them going. And then forgot about them.
I hope that Mr. Mike Wood can go visit the horde and see first hand what he thinks. In this case, I think it's real.