Wow, this is really neat stuff. I adore your work on the Ziess Ikon Contessement (however you spell it).
I was given a Keystone XR33 when I was about 11 or 12, and it is now on the shelf with a number of others. When I found it in a box a few years ago, there was still a roll of film inside, and when developed, it had four visible images from the early 80's. There were photos of our old house, and my best friend at the time. It was a real blessing to find such an unexpected photographic time capsule.