This Marlin manufactured mainspring screw is for the model 1892 and 92 lever action rifle and is in very good condition exhibiting a grayish brown patina with light slot wear and possibly some specks of rust. (file photo)
Note: Marlin model 1892 and 92 rimfire rifles with the following serial numbers have been observed with this part:
1892:
92: 400471 & 406506