So, I've now got around to disassembling the Contax. It looks like it's not a pilot project after all, but a conversion from 1959, as you can see from the photocell. On the other hand, the photocell may also have been replaced in 1959, it is not known for sure.
In any case, the retrofitted flash connection is very interesting: It has 2 breaker contacts, one under the shutter release, which is closed when the shutter is pressed, and one at the bottom of the housing, which is closed when the shutter is released. When the shutter release button is released, the upper contact is interrupted (the lower one is closed until the camera is cocked again), so that the flash does not fire continuously.
So, unfortunately it doesn't seem to be a pilot project, but it is an interesting modification. The question is, who might have done something like this, a gifted camera repairman, or perhaps even at Zeiss itself?
Take a look at the pictures:












Ulrich
http://fotos.cconin.de