Above the selector switch, "R.F." and "S.F."
Above the safety switch, "S" and "F"
I am particularly interested if the letters "ABC" or "TOC" appear anywhere on the weapon. I am also interested in knowing what manufacturing marks are present on the barrel.
Here is a picture of the weapon, and if you're not already familiar with it, you will notice the similarity to a 1921 Thompson, but the Hyde has a round receiver.

Also, can anyone identify the type of rear sight that is in the picture? This is a picture of the rear sight on a Hyde.

Thanks in advance!
David Albert
dalbert@sturmgewehr.com