this stamp combination ?
 

On a "banner" 1937, the v block, matching 4-digit serial numbers in the three ususal military places, and last-two numbers on faces of parts, like in the middle of the sideplate etc. Except the barrel does not have a block letter with the matching serial number.

On the extension / slide, on the left side of the chamber, there is a crowned U but set sideways horizotally, in front of the serial number.

On the right side of the extension / slide, where there are usually acceptance stamps found on military Lugers, there are NO stamps at all, just plain, no shadows of or signs of buffing. That part of the extension is just as high as the rail below, and the rails fit properly closely interlocked, being evidence of no extensive buffing.

Were not all commercial Lugers stamped with hidden sideplate numbers, on the bottom surface etc. ?

From this description of stampings, can the pistol tell its story consistent with known versions. ?

Yes if it stayed in privates hands, if it went into the police or army service you will usually find hidden & military style of numbering.

So ....banner 1937, no commercial serial numbers or hidden placements .... but no military acceptance stamps, and no police safety .... no suffix on the barrel, the gun is confusing to me ....

Alx, check the myriad of luger literature out there now, including the new treatise "Mauser Parabellum" by Hallock and Van de Kant. The "hidden" serial placement on commercial lugers went away when Mauser took over production. The commercial production was reserved for the suffixes "v" through "y".

Alx... From your discription the Banner sounds just like it should be. I think the hidden placement was something that DWM did with their commercial guns but I believe Mauser numbered all of their guns the same. What changed was the the proof and acceptance stamps or lack of in the case of commercial guns. Police Banners will have an Eagle C, F, K, or l on the R/H side.

You might want to consider buying the new book THE MAUSER PARABELLUM.