As luck would have it, we had to travel to town again today, and I got the fixture!
Sadly, it didn't work when I tried it, and it turns out one of the lampholders has a piece broken off it. Don't know if it could have happened in shipping, or if the seller never actually tested it like they said they did. Luckily, the lampholder is not broken in a way as to impede its use - the lamp just happened to slip out of it somehow. In conclusion, the fixture does work perfect! I've still asked the seller for a partial refund, though.
But get this! I opened this thing up to see what was inside, expecting to find an early electronic ballast with a TO3 transistor and what-not. What I found is the most amazing and awesome low voltage DC fixture I've ever seen. This thing uses a magnetic ballast, paired with a vibrator!! The vibrator converts the 12V DC to AC (at 60 Hz, even), and the ballast is actually an autotransformer, stepping the 12V AC up to whatever the OCV is, and serving as the ballasting impedance. That's so awesome! There's not a single solid-state component in this thing!
As it figures, the cigarette lighter socket I use with my 12V power supply decided to break as soon as I started playing around with this thing, so I need to devise another way of powering it. Once I do, I'll start measuring the OCV and current.
