I love track frames, Japanese, British, Italian and French. In fact I guess I'd be into a vintage hand-built steel track frame no matter where it was from.
If you're like me or just happen to be into Velos de Piste (= French for track bikes) you might want to look here: http://www.fantome-fixed.blogspot.com/. Fantome Fixed is a new 'blog shop' selling only french Piste frames and at the moment they have PLENTY of them for sale. I've no idea about the prices but they're all très beaux.