This Winchester manufactured magazine plug is for the model 1906 slide action rimfire rifle and is in good condition exhibiting a grayish brown patina.  (file photos)

Note: Winchester model 1906 & 06 slide action rimfire rifles with the following serial numbers have been observed with this part:

Below 100K: 81649

100K: 162122 & 163781

300K: 312061, 333347 & 359560

400K: 405314 & 442486

600K: 611843 & 655997