Mike,
I suspect that your explanation is correct and that the markings were removed at the time of the conversion. I rechecked the action and whoever did the grinding/ stoning did a good job in matching the surface finish of the front and rear rings. I wonder why they felt that it was desirable to remove the markings?
I should correct the statement above regarding the origin of the Wehrmannsgewehr. Jesse Thompson, in Alte Scheibenwaffen Vol #2, gives a good history of its development. Both the rifle and the matches that it was used in clearly precede WW-1.
Otto
