I just purchased an Izhevsk M91-30. It has a stock that has no shellac, oil, I think, only. It is a hard wood stock with a wrist bolt. My question is this, the Soviet mark has been taken off. A file or something like it. Below where it was is a simple small square, no line in it, stamped in the metal. All of this was done before bluing or re bluing. Anyone have any ideas? Thanks.