Hi Jim - I don't see any markings on the receiver except for "K98". Yes the front sight guards are curved and the bayo lug is where you stated. What I have noticed upon closer inspection is that the receiver, butt plate and stock all have matching numbers. This rifle was in a closet of an older fellow who recently passed away, and God only knows how long he had it and where it came from. His widow was kind enough to give it to me.