Diana Model numbers.... not even including "original" and "Diana"

[MDriskill]

That sounds exactly like my old quarter-stock 27, which likewise has no model number. There are other details of it linked in post no. 7 above.

Also check the chamber length, which measures 290mm from the front of the breech jaws, to the front of the barrel block. That distinguishes the 27 from the contemporary model 25, which was similar in construction and appearance but shorter.

[AC99]

That sounds exactly like my old quarter-stock 27, which likewise has no model number. There are other details of it linked in post no. 7 above.

Also check the chamber length, which measures 290mm from the front of the breech jaws, to the front of the barrel block. That distinguishes the 27 from the contemporary model 25, which was similar in construction and appearance but shorter.

I have just clicked on the link in your earlier post with more detailed pics and descriptions and the distance from the front of the breech jaws to the front of the trigger block (which is what I think you meant) is 290mm so it seems mine is a mod 27 but with the addition of a locking screw on the barrel hinge bolt which would stop the bolt turning. Also on mine the R/Sight is adjusted by means of a serrated wheel rather than a screw but I am not sure if this is original or a later replacement

[MDriskill]

Interesting, thanks! I would guess those are minor production variations that happen over time. The improved breech may indicate yours is a bit newer than mine.

The production date is typically stamped under the breech block, visible only when the action is open. Mine is "9.26" (September 1926).

[AC99]

Strangely, there does not seem to be any markings at all where you have indicated and the corrosion in that area is not too bad with most bluing intact. I will take a closer look in the morning in daylight, but thanks for the info.

[AC99]

I have checked again for a date stamp in the region you indicated but there are absolutely no markings there and I also removed the metal butt plate but nothing under there either. All a bit odd since all my old Dianas have date stamps - usually on the butt.