You seems to have found a GREAT rarity
"Have been looking for a nice Spanish Mauser for ages, and this pitiful thing is the best by far."
Why pitiful? What we can see so far is 100% matching. The stamps in the wood tend to disappear first, and the fact that the 380 is still visible below the receiver ring indicates that the stock has not been maltreated or subjected to climatic extremes. The buttplate seems to match the wood very well - this is the place where shrinkage or sanding of the wood shows up most obviously. In that connection, one has to accept the individual and apparently very old decoration as "part of its history", much as I dislike this often misused phrase. But read on...
What puzzles me is the crown (?) over a fraktur (black letter) "T" after the number on the receiver. It looks like a German inspector's stamp, but that does not seem right for a weapon made for a contract that was not for the German army. When you can, please post a photo of this in a larger size, as the form of the crown may help to clarify this point.
I can only find one instance of a DWM Mauser thus marked - on the last page of the Appendix in "Mauser Military Rifles of the World" - a summary of Boer Mausers. Under "Serial # Range, Item 4, one can read: (My italics to emphasize crucial points)
"1-10,000 No letter prefix.
Long Rifle (29" barrel).
On side rail: "Deutsche Waffe- und-Munitionsfabriken" over "Berlin"
No receiver crest. Straight bolt handle.
...3. One observed DWM rifle (18xx) has no circular cartouches, but does have German military quality inspection marks (a crown over a fraktur letter) in four location.: the left side of buttstock, left side of receiver near the serial number, top of bolt handle, and top of barrel under handguard."
It looks like you found the second military-marked Boer Mauser. And the decoration is indeed part of its history, having been (unprovable, but very likely) applied by its Boer owner.
Pitiful? I think not.
I think that you should purchase a copy of that book in acknowledgement! And write to Ball with some photos, so that he has the info for any future editions.
Congratulations.
And for heaven's sakes, DON'T remove any of the decoration or finish, which is probably all-original.
Fate of some Boer Mausers
A friend, knowledgeable about Mausers, recalls seeing a photo (or photos) of British soldiers burning huge piles of captured/surrendered Boer arms, upon the conclusion of the South African War.
I remember reading about Boers throwing their rifle bolts into rivers and breaking their rifle stocks against trees, before surrendering their arms.
It was a bitter war with destruction of farms and concentration camps. Some Boers would not accept the peace agreement and were forced into exile.
