Okay, looks like I figured this out. I popped off the metal back of
the watch case, and found that it's a Ref. 3479, made of 18k white
gold. The band is made of the same material. I also see the movement
is a 23-300. It's the same watch as pictured here, only it appears to
be in much better condition:
www.solid-watch.com
This is the first time I've seen the movement of a mechanical watch in real life, and I must say it's quite neat!