Thanks for the tips.
I was kind of afraid it might be made for PCB connection. But the size is so close-looking to some of the connectors I've seen.
One thing I hadn't known or considered is that while I might be able to make a connector work, they're not designed for it, so it there's a great chance it wouldn't reliably work well..... compared to Molex or Dupont, which I like, or even IEC ribbons -- which I don't like but have to admit they hold just fine.
Anyways, this solves my problem. Those were less-than-carefully-ordered anyways, so I'll switch to something with soldering lugs on it on my next order and try to use some perf to make a little breakout board to make use of those parts.