These pre-1912 guns typically lack the "Nitro" proof stamp that later models were required to have under German law. I doubt a 1910 made gun was much weaker than the same gun made in 1913, but I could be wrong. Would a pre-1912 gun in good condition with tight lock up and steel barrels require very low pressure BP-like ammunition? Or would most (not super high pressure) 2.5" ammunition be acceptable to fire in a gun of this vintage? I would be talking about any 2.5" shell from RST, Polywad, but also possibly up to the 2.5" offerings from Kent.
