This is a standard steel trigger guard from a Winchester Model 70 rifle.
Bluing - N/A - The bluing on this trigger guard is essentially gone, and a brown patina has emerged in the metal.
Metal - Overall, this piece is in excellent condition. Despite the bluing loss, there is no rust or rust pitting on the metal, and there are no significant nicks or tooling marks. There are a few minor scratches from normal rifle use.
We use the NRA Modern Gun Condition Standards Grading System for grading part conditions. You can read about it HERE