Hi Again,
I realize the barrel flats are hard to read, I will try to describe the marks first the numbers 1835.26. then NPf a cursive styish F inside of an E that seems like it could be a barrel maker mark? some kind of an eagle the tubes have an S and a K one tube 16.0 the other 16.1 (right barrel), the tubes also have the F inside the E. Between the ribs 1200.0.4388.25.15 5 160
Thnaks Jeff G.