Larry, yes the button is checkered, but as pcke2000 said, it's for the cleaning rod.
Jon, thanks for the date.
pcke, I, too, noticed the lack of rail slots when I bought her. I'd love to get a 1940, but I'm just glad I got this one for what I did.
Bubbaz, Thanks. I'm pleased with the clarity, but the orientation of some from what the original was have a tendency to bug me.
Anyone know of a source for the gas tube. Mine is pitted, but looks serviceable. All the same, I'd like to either replace it or have a spare.
I'm working on a trade with a good friend to get his Finnish capture. He says it's a 1941, but he didn't provide a picture of the receiver top. Just of the serial which I'll post in another thread.
Again, thanks all.