Looks like stock was sanded fairly heavily, the wood seems at level with the crossbolt. Also most BLMs had Durofol handguards rather than laminate wood but wood is OK on that maker. Do internal gas system parts match, and the firing pin housing, flaps, bolt? Definitely get and install one of the Apfeltor shooter kits, I know the rear ends of these receivers can get whacked pretty good without a kit, why take risks of damage or injury. Nice rifle, congrats!