I had a discussion with a fellow collector regarding the origin of the 9.5×57 MS. Both Dixon and Hoyem state that it was an Austrian design, but the Wikipedia article states that is was actually a British design by Westley Richards and Eley in 1908. The Eley drawing is titled “Westley Richards .375 Cartridge” but not dated and DWM’s case number 531 is designated “Pürschbüchse Kal. 9,5 mm Mannlicher-Schönauer” and is from 1908, but there is not any definitive information about the exact date (the answer would be found in DWM drawing number F348, but as far as could be determined there are no copies, if any actually survives). There is a Mauser drawing 11242D of DWM case #531 which is dated 1921 and refers to F348. The earliest known Austrian production is G. Roth and its case number 811 was assigned c.1910, and if this was designed by Steyr on an earlier date, there is insufficient information to support it. (Dixon Ref A50).

Regarding the “.375 Westley Richards”, this is an excerpt from a WR c. 1909 catalog (dated Jul 12 1909 on the cover):                         

          Kynamco dummy

  This is the NGA Bushmaster load from South Africa. Made from 30-06 cases with a GM belted bullet.