first SLR w prism?

Common opinion is that first SLR camera with a pentaprism is either Contax S or Rectaflex. This is important issue since introducing of the pentaprism is very significant step in development of the SLR cameras (there are arguments for either Sport or Exakta).

Based on the serial number of this camera (595171), we can suppose that it is pre-WWII product. Another facts to consider:

1. Shape of the prism cover differs from other known versions. It is original, not made later. It os chromer from outside. Inner surface is painted in black.
2. Name plate is without name on it. May be some different variation of the name was planned.
3. Name plate has a factory rivets where usual Exakta has threaded holes.

Relatives of the first owner of this camera told us that it was presented to him at the factiry right after WWII. They don't remember exact year, but it was already in USSR in 1947.

Chrome cover of the name plate and rivets is identical to standard Exakta covering. But surface of the prism cover is more rough. It seems that the cover was made at experimental lab of the factory. It is interesting to us to learn if this same with Exakta Diamant since our camera looks similar to it. May be our camera is the prototype of the Diamant?

Leather case is usual, so it is bit small for the prism (you can see wear inside). The camera is in working condition, but there are two issues:

1. Self timer lever do not stops in the winded position.
2. One of the prism cover screws is missing.

Not Sold for US$ 15.000,00