Thanks to all who replied.
I don't think I ever said I "wanted it to be a trench gun", not would I be bent-out-of-shape because it isn't - which it isn't. I now have enough basic knowledge about military issue trench/riot guns now to know IT IS NOT a legit trench gun or riot gun!
Some on this site seemed to be totally consumed with "if it ain't a legit trench gun, it ain't sh@t", and not worth talking about.
On the other hand, as an example, there is written history that some Remington Model 10A Trench Guns morphed into "riot guns" after WWI. Unfortunately, as "bigskybound" eluded to, there is not much interest or research into what happened to WWII and post-war shotguns. Yes, many went off to law enforcement and prisons, and some on to Korea and Vietnam - but what about the whole Civil Defense thing through the late '40's and '50's?.
I'm still curious about the lack of factory Stevens/Savage markings, and possible history of "CD" markings, which was my purpose in posting on this respected site - to ask the general combat shotgun gurus (not exclusively the trench gun gurus) their opinions.
Cheers.