Over a period of several years, I was in contact with, and visited
several times, Kai Bittner in northern Germany. He was involved in a
club (Verein) which had to to with historical computing hardware; they
also have a sort of museum. We are (in his case, were?) both fans of
DEC hardware, but had different interests; over the years, I got some
hardware from him, and he got some from me, and we both always thought
that it was a fair deal.

His mobile-phone number and email address(es) no longer work. He seems
to have disappeared.

Does anyone have any contact info for him or his club (which IIRC had
something like "Rechenkabinett" in the name)?

Please reply by email to helbig (at) multivax.de; my usenet access is
limited at the moment and also there is no reason for the answer to be
public (anyone also interested can email me and I can pass on what I
have if the source(s) are OK with that).