I was just looking at the 1953 Winchester Model 21 booklet and noticed there were no roll-stamped markings on the left side of the left barrel of any of the guns showing the 21-1 through 21-6 engraving patterns. Other places in the booklet where the left side of plain guns are pictured the roll-stamping is visible.
As to the forearms, a friend of mine has a fully optioned up Parker Bros. BHE-Grade pigeon/trap gun that has two complete forearms, one slim and one beavertail.
Thanks, Researcher. You have confirmed the absence of the Winchester stamping on my 21-5 Win 21.
Yes, it is possible that my M21 had two original forends---now it has an original sliver forend and a non-original beavertail forend. Personally, I prefer the beavertail forend on a single trigger gun.
Bill