It may very well be an Sauer example from circa 1890, but the cocking indicators, horizontal rib, selfcocking stamp atop the tubes, Calibre(CAL: 181/182) all point to a 1892 production. The blade type indicators seem to appear in the 37k series. The early psuedo sidelocks still had the hammers in the frame. I can't really read the "CAL: ?" stamp and am curious if the other scattergun tubes have similar stamps. Usually the "CAL: 181 S" stamp is seen along with "BERN" and was exported to Switzerland or went to Switzerland via Eduard Kettner. Usually after the "592H" will be the initials "gKH" with the "g" being sort of a lowercase script. I'd say the pattern welded tubes were sourced from Belgium and the rifled tube is cast unless stamped otherwise. What type rifling does it have(Henry)? There are several variations within the 11.15X60 and unless a 11mm Mauser just drops in, and probably anyway, I'd make a chamber cast and slug the bore just to eliminate the variables. But extra effort and expense was dedicated to craftsmanship and pattering.
On the combo, what are the initials on the pattern welded tube next to the rib? Also, I've been chasing the "CRF"(???) stamp as seen on the rifled tube. I think it to be a large "C" with a "R" and "F" overlapping. Many times it is seen on the lower rib as well as on the tubes. Both sets wear a multiple/double "caveman" series. Nice find.

Kind Regards,

Raimey
rse