Leica visoflex ploot ID (leica gun)

[randy6]

I'm trying to date this ploot well at least almost a ploot serial 2321. Okay this is what I know. In 1938 a leica gun was made and first thought of in 1936. The 1938 model doesn't look quite like this. I found a photo of a 1937 model the long telescopic eyepiece is dovetailed like this one but chrome were the eyepeice connects to the ploot. Mine appears to have a different conection still dovetailed but black painted brass conection and can be permently screwed in the ploot. I do not have a stock. The lens attached is a dallmeyer 12 inch with an infered filter. ser 205965 Can anyone help me date this? and how many made?