The Lyman 48 WJS was delivered on standard rifles from the factory, when the rifle was ordered with a receiver sight (the Lyman 48 WH was delivered on marksman, national match and bull rifles).
This is an early style sight (pre-1947) with a full block, requiring inletting in the side of the stock to accommodate the mounting block. This base and slide are number matched with U74. This sight has the larger "target" knobs, a 60-point scale, and micrometer adjustments. The aperture and mounting screws are included. This sight is in NRA excellent, almost mint condition. There is no finish loss, damage or sign of use.
We use the NRA Modern Gun Condition Standards Grading System for grading part conditions. You can read about it HERE