s/n is 42247.  The peep sight is attached by a screw/bolt in the left side of the receiver which has a milled relief to provide a flat surface and by a tab screwed into the back end of the sight which protrudes into a hole in the back of the receiver. I haven't seen any pictures similar to this. It appears to be professionally done. Also, the barrel is nicely crowned and there is no missing blueing there or under the peep sight.

I don't plan to restore the rifle; just curious about its background.

Thank you for your comments.
Wade