Well, I went wandering through a big swap meet where I happened upon a Canonet GIII QL19. Just like the QL17, but a fraction of a stop slower lens. I was lucky enough to pay only $2 (Canadian!) and I retreated to my cave. When I emerged, the rangefinder was removed, cleaned, and re-aligned.
This is my first canonet, and I have to say I've quite impressed with how the rangefinder functions. It is bright and contrasty, with good automatic parallax adjustment. Here's a pic with my new "El-Cheapo" lighting rig:
