Chris, the first bit is what is (as I understand it) now referred to as the DMC, but would probably have been referred to as the VAOS section when these were packed.
I think I was being slightly flippant when suggesting some stores man had got it wrong.
I've found these VAOS sections in Clive's paper on NATO part numbers - I hadn't checked there before, as these parts are too early for NATO numbers and I'd forgotten there was a big list of VAOS sections / DMC codes there.
Clive, in that list you refer to W2 as obsolete for 'electric cable and wires, primary cells and miscellaneous electrical stores'. Y3 has become 'wire and cable, electrical cable drums'. That would explain why some are labelled with one code, some with the other. I could see that it would be possible for stores to escape re-classification one way or another.
Being strict about the definitions, the signals sections don't actually refer to cable unless you count it as 'equipment', so again I suppose you might see that all cables irrespective of their use might get classified into the VAOS section that refers to cables??
Chris, these boxes I think also pre-date the Hellerman tools, and are probably a lot more contemporaneous with Clive's illustration! If you look in the original photo, you'll see the ceramic twist connectors bottom left.