The Shellac finished rifles that were a product of the postwar Sovieticon refurbishment programme are important historic pieces in their own right which should be preserved. I have several weapons (U.K. de-acc) that went through the programme although they didn't finish my PPSH41 in Shellac for some unknown reason. I think that there is general agreement that the Soviets didn't use Shellac during WW2 but less certainty on exactly what if anything was used. I believe that it is a distinct possibility that sump oil may have been used to stain at least some Soviet rifle stocks during WW2 and that the possibility shouldn't be totally dismissed.