http://www.ussrphoto.com/UserContent/1082015_zenit proto.png
Nº 5000002, 1950, condition B+ € 5.000-7.000
well preserved Zenit pre series or test camera engraved No.
5000002 from the property of an employee of KMZ. Most of
its characteristics are those of an early Zenit, e.g. the
“Square Logo”, while it still has a few minor details in
common with the first prototypes of the Zenit as well. It
mainly differs from the series model by the execution of the
prism housing and the eyepiece, which both seem to be one
of a kind. Dr. Milos Mladek, well-known expert in Russian
cameras writes in his expertise: 'After a thorough
examination of the camera and after having compared it
extensively with both a Zenit prototype and a “Square Logo”
model Zenit, we consider this camera a KMZ factory research
model that was very probably made just before the series
production of the regular Zenit to test the new rounded
shape of the prism housing and moreover to test a special
diopter-adjustable eyepiece (+/- 3 diopters, three lenses in a
non-rotating mount, very well made - regrettably it later did
not make it into series production). It always was highly
unlikely that KMZ would have started series production of
the regular Zenit body without having tested the new shape
of the prism housing: here is the test sample. - It comes with
a later lens, cap and case'.