And if anyone is curious about the state of the machine: it seems to move quite smoothly. The cord was in a horrific state:
But once I bought some new lampcord and other bits at Lowe's and rewired it, it seems to work fine, although the motor belt is about to break. It also needs a new bobbin tire (the old one shattered when I tried to pry it off) and the bobbin case is missing. And it comes with one cam. It says 691, not 651 on it, by-the-by.
Once I clean it up and get the above parts, I'll how it stitches. One of the things I was astonished to discover is that the light actually still works. I was really expecting the bulb to be dead. But then, I'm a total novice at this machine repair stuff. Wish me luck!