This screw is the forward-most action screw, which holds on the magazine cover / floor plate. It is an original Winchester part.
New condition screws are original Winchester parts which have never been used before.
Excellent condition screws are used with minimal tool marks.
Very Good condition screws are used with perfect threads, but may have very minor tool marks and/or bluing wear, but no rust or other damage.
Reproduction screws are new and are dimensionally identical to the original Winchester screw, but do not have the same polished metal of finish as the original screws.
Reblued screws are original Winchester screws which have been polished and reblued to closely resemble a new original part.
We use the NRA Modern Gun Condition Standards Grading System for grading part conditions. You can read about it HERE