Mauser Argentino models 1891 Mexican stamp questions ?

I just bought an Argentine Mauser 1891 and I wonder why there is a Mexican stamp on the stock.
Anyone have a little idea?
THANKS.Attachment 138680Attachment 138679

That's a puzzler for sure. The Mexican national crest has changed many times over the decades so that helps pinpoint the era somewhat. The last time Mexico used a forward facing eagle with wings folded while atop a nopal (prickly pear cactus) was 1893. Your M1891 might have been taken on strength as a trials rifle because it was around that time Mexico was looking to replace its outdated arsenal of Trap Door, Model 1865 Spencer, and Model 1866 Winchester rifles. Mexico chose the Gew 98 so it obviously took them a few years to decide and the Gew 98 was soon replaced by the Mondragon autoloading rifle. Your rifle with that stamp is likely one of a very few.

Crest is partial removed and ave argentine marks, caliber is 7.65x53

Many M1891 Argentine rifles were donated by Argentina to Paraguay during The Chaco War 1932 to 1935 and had the national crest ground off so as not be seen as supporting Paraguay over Bolivia.