I think you said it all... fits factory dovetails as a replacement sight... but with a home made elevator and a ground out profile... no "notch" left.I am not a collector of anything specific. I would not be surprised if the sight you have illustrated is a generic model produced by a sight manufacturer ( Marble would be my guess ) supplied to a number of the major manufacturers back in the day. I am pretty sure I have seen that sight on both Winchester and Remington bolt guns and some model lever guns. I do not believe the elevator is original to the sight.
The groove on the face of the sight blade originally had a white lining (paint?) but it fell out.I suspect the top of the sight has been dressed out. I'd expect a well defined notch.
Not if it was an "Express" sight.I suspect the top of the sight has been dressed out. I'd expect a well defined notch.




























