Presence of MADE IN U.S.A. stamp means after 1922. Shape of ejector rod knob mans before 1928. I'm not sure when the .32 W.C.F. stamp was changed to .32-20, but leaving that aside I'm thinking mid-1920s for this specimen. Which is beautiful, by the way. As others have said, wrong stocks. With a strong light and good eyesight, you might be able to pull the pencil serial number off the inside of the panel and figure out what gun they were on first.
I have only one .32-20, a refinished 1915 specimen. If I ever came across one like yours, I would buy it in a heartbeat.
I certainly agree fully with David's last statement.
On the extractor rod knob, 1927 is about right for the .38 M&P. But we've seen the early style knob on .32-20 HEs that shipped later. My thinking on that is that one of two things were going on:
Either barrels were made up ahead of assembly and had the double step machining on them, so older style extractor rods were held back to fit them, and they appeared on .32-20 HEs that were shipped later.
Or else, the rods were just held back because they didn't want to change the machining process for this particular model, which by that time was not selling as well as the .38 M&P. (I tend to favor the first theory.)
I have yet to see a single example of a .32-20 HE with the barrel shaped knob - they may exist, but I haven't seen one that I can recall. If someone has one, I'd like to see a photo of it.
Jack