Thanks, I think I'll cross that one off my ldream list. They are beautiful though.
I wouldn't cross the Certo of your list yet:
The Certo Six is actually a pretty simple camera to work on. I've never worked on a Super Isolette but I have worked on Super Ikonta B's and C's, Retinas, Rolleiflexes, Leicas and my Telka.
I found the Super Ikontas hardest to work on because getting at the shutter requires removal of the lens and the focus mechanism.
My Certo Six had a few issues, when I received it. Most Certo Sixes have bad rangefinder mirrors, but this isn't hard to put right. The shutter is easy to clean without removing from the camera, and you just unscrew the lenses to clean.
The Certo; is by far the sharpest lens of any vintage folder. Wide open the f2.8 lens is sharp edge to edge. It seems to have the same sharpness and contrast as my Hassy 80mm. The rangefinder is relatively bright for a folder, and it will compensate for parallax. I have never seen a more rugged medium format folder with it's thick steel struts and solid body.
Some of the ergonomics of the camera leave a little to be desired like; you can't close the camera with the lens cocked, focus is weird since you use a little lever, as is the shutter release, which is also a lever.
You buy a Certo 6 for the images it can produce.