Here is another such mount and scope for the M-Sch, this time an earlier small 22mm diam. Kahles "Mignon 4x" scope with a nearly complete mount. It still awaits being mounted on my M1900.

About the popularity of the Vienna-style snapper mounts in "Europe": I will never call them "Springer mounts", as Springer's Erben was only one of the many gunsmithes in Austria who fitted these, and those three-legged ones on the M-Sch were certainly not made by Springer!These mounts were quite popular in Austria. You find them not only on Mannlichers, but also on many break-open rifles of Austrian provenance. Germans on the other hand from the start preferred their German scopes mounted by german gunsmithes with their familiar claw mounts. So you rarely encounter M-Sch rifles mounted with Vienna snapper mounts in Germany.In Germany from time to time you encounter side mounts too, the pre-WW1 Greifelt/Suhl one looking exactly like the later American Griffin&Howe.
Though Steyr dovetailed their "factory" bases into a saddle soldered on the barrel shank, many individual gunsmithes cut the dovetails for upto 4x scopes directly into the receiver ring, both for snapper or claw mounts. They continued to do so until about 1960.Others used saddles soldered either over the receiver ring or the barrel, so the kind of scope mounting is completely unsuitable for dating!