This Winchester rear scope mounting block is for the early bolt action rimfire rifles that were produced in the 1930's and 40's and measure 1" in length with a hole spacing of aproximately .600" (center to center). This block is stamped "" on the side and measures .460" tall. The overall condition is very good exhibiting a mixture of thinning original finish with a brown patina. The mounting screws are sold separately.  (file photos)