The bolt release markings, 'cross' and 'star-cross', are Spanish 1893 markings.
Possibly the Ludwig Loewe factory used small parts from the Spanish Contract to complete a Boer Contract?
(Some countries' contracts for Mausers will have small parts, with a 'cresent moon', from the TurkishContract and the "mix" is perfectly correct. These markings seem to have been a factory aid to identify parts, while filling simultaneous contracts).
The broken stock is interesting. Many Boers tossed their bolts and broke their rifle's stock when surrendering to the British.
I would not mess with your Boer Mauser and leave it, as is. Some Boer Mausers have no special markings, initials, or crests. They were often purchased by the Boer Citizen and were personal property. The letter scratched into the stock could have identified the rifle's owner.