+1Use the Warne Maxima QD LOW rings or the Leupold Low rings. Warne makes the Leupold rings per my conversation with the Leupold Custom Shop. Add the long eye relief Scout scope that your budgets affords. I personally like the Leupold scopes for this application.
Yes, there is a separate piece that slides into the dovetail that has a threaded hole in it that a screw passes through the rail and into it. Makes for a solid attachment to both receiver and barrel.On the XS Lever Rail, does it utilize the dovetail of the rear iron sight as an anchor point? I know the Lever Scout Mount does, just not sure about the longer rail.