Congrats on the find! Nobody else had mentioned this yet, but if you plug a regular guitar cord into the 1/4" jack, you'll only hear the bridge pickup, and the pickup selector will appear to be dead in two positions. There's nothing wrong - the 1/4" jack is a stereo jack, not mono, and a regular mono plug will only get one pickup's output. On the current instruments, the output is usually mono to be more wireless friendly. You won't get any output at all until you have a pair of good 9v batteries in there. And on a Series instrument, the battery life is really short - maybe 40 hours (vs. 1000 for something like EMGs). The power supply looks like this. Once you know the bluish color you're looking for, you can't miss it - it's small, but built like a tank

Some of the boxes are black, but I think that's a lot later than this guitar. While you're looking for it, keep an eye open for the special cable that you'll need to connect this 5-pin XLR up. The standard cable has one end that has the same shell as a standard mic connector (of course, 5 pins instead of 3) and the guitar end is a right-angle XLR which you don't see too often. Enjoy! This is a real treasure! David Fung