Looks to be maybe a one piece base and Leupold rings??? Hard to tell...
Its a leupold base fore sure. If you are shooting w/in the limits of the elevation in your scope it will be solid enough. not a super high end mount but quality and secure. Before you look at Nikon scopes though give allen a call ^^^ and at least give him an opportunity to put you into a scope... he will not disappoint.