The BNP marks are British Nitro Proof. These are the marks made by the British when it was exported or left military service and pressure tested. The word England is also an import mark.
It is not a Savage, it would say "US PROPERTY". It is not a LONGBRANCH, it would say so. And that hole in front of the bolt would be 3 small holes, not one big hole, if it were a Longbranch. These marks may have been removed, but this seems unlikely. It is a lot of work to remove that much metal. Are they any other marks on the parts? S in a square will be Savage parts. I would check the front sights and look for initials there, that may indicate which British factory produced it. My guess is that it is a Birmingham, they were often marked with a "B" and you may not be seeing it. But someone who knows serial numbers might have a better idea.