Ks in a jagged circle - multiple tube task effort by Louis Kelber, one of the best rifled tube makers.

Imperial Eagle with "Crown" over "G" preliminary proof more than likely of the single tube only with a solid projectile with say 3 times the black powder powder charge and 1 1/2 times the bullet weight. Here I think the Austrians used two lead spheres.

Stylized brace of SS are the initials of the tube knitter and it may have been one of the Schilling boys, or some other S last name, possibly with a 1st name like Sylvestr.

Kind Regards,

Raimey
rse