That's a fairly fancy double rifle drilling - very nice, and in usable chamberings, too.
Drillings that used two rifle barrels and a single shotgun barrel are rarer than double shot over a rifle barrel.
These were harder to make, since, like a double rifle, the rifle barrels must be very carefully regulated, that is, aligned during manufacture to shoot to the same point of aim at a given distance.
This requires more precision than regulation of double-barrelled shotgun barrels, which are used at shorter ranges with wide patterns of shot where a small misalignment won't be significant.
I would WAG it's worth at least $2500 or more (probably more), depending upon condition details.
(these are some combination gun configs, with some drillings in the middle, vierlings at the bottom - cape guns & 5-barreled versions are missing)
I don't recall ever running across another Double Rifle drilling that had two different large rifle chamberings, though ( 9.3mm & 9mm) - R U sure you've posted the markings correctly ?
The ones with different chamberings were usually vastly different (like maybe a 9.3 with a .22 cal), and the rifle barrels superposed with the shot barrel on the side.
"Guss Stahl" = cast steel
"Fluss Stahl" = mild steel
"Kruppessen" = barrel maker fromm Essen, Germany
"Henry Vogt" may have been a former owner or importer.
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