--I've discussed this with Philip, and we've not come to a firm conclusion. According to lore, there were never any six-color caps that were issued. This one is odd:
On a normal commercial/ surplus item, there might be a bogus DLA #.
On rare occasions, one might see a DCA #, and that would qualify the item as being a special contract item, but, according to a source who seemed to know quite a bit, DCA's did not come about until the 1990's.
So, the question is, how would anyone known to have come up with a DCA back in 1984?
There's an historical incongruity.
Like most things I ask questions about, I expect that this is easily resolved by one with knowledge, but intensive use of google hasn't nailed this one, yet.
I wouldn't ask for help if I hadn't already tried.