The 8x58R Sauer ctg. is hard to find, although it was a fairly popular combination target and hunting cartridge in the early 20th century. You would have to make cases from 9.3x72R cases. They are available but pricey and would require forming dies in 8x58, which are also available but only on a special order basis. And you might have to use Berdan primers unless you could find Boxer primed cases.
The cartridge is similar in power and uses to the old .32-40 Winchester and Ballard; basically a decent deer cartridge at the usual ranges we see in the East and coastal NW. You might have to slug the bore to find out if it took the .318 8mm "J" bullets or the .323 "S" bullets, although if the usual Germanic thoroughness were followed by the maker, that info would be stamped on the flats of the barrel where they mate with the "water table" of the receiver. You need to remove the barrels to see this.
If the maker was H. Barella, it is a good quality drilling.
