The mid bead was probably added later as this is a Field grade. This would not affect the value if it is in the proper place on the rib,and it is absolutely dead center. I would be more concerned with the blued receiver that effects the value in a big way. I would say at least by 50%. You must also be sure the barrels were not Hot blued if they were done at the time the receiver blued. If you are looking for a gun that will maintain it's value,this is not the one.