David, I suppose the nearer the distance the more optical challenging it becomes to correct the rangefinder. They gave up the concept in later times as it turned out not to be competitive to SLRs anyway, I suppose.
I am a little bit further with my problem now. From what I've learned from cameraquest (the site you mentioned), I have the first version of the lens with the "eyes" from the second version. According to cameraquest, something that should not be possible mechanically. The only way to accomplish this is to "frankenstein" the eyes of the second version with the foot of the first version.
As it seems, it is not possible to adjust the eyes correctly as there are about 8cm in range missing, that means: If I adjust the eyes such that the horizontal alignment is correct for the greatest distance the scale shows 58cm while focused on an object 50cm away and the scale shows 80cm when focused on an object 88cm away if adjusted from the short distance. In either case there is a vertical misalignment of about 1/3 of the height of rangefinderpatch.