Post photos, please! Your description, split bridge,German commercial proof marks,seems to be of a civilian/commercial rifle built on a M88 "Commission" action than any Mauser. The issue "Boer War" rifle of the Orange Free State and others was the M95 Mauser in 7x57. No true Mauser from the 1888 Mauser Belgian experimental on had a split bridge. Of course, it is documented, that some Boer fighters used privately purchased rifles of sporter or military configuration in that war.