Have it examined by a good gunsmith
Based on a single source* the Model 1912 7mm Mauser, very similar to the German Rifle Model 98 was a standard issue for the Mexican Army in 1935. Mexico adopted the 7mm Mauser Model 93, in 1895, a similar rifle to the Spanish 7mm Mauser Model 1993. During the period of 1910-1920 many difference rifles were obtained, including the Japanese Tpe 38 rifle. In 1936, a Mauser of Mexican design was adopted. The design was a 7mm Model 1936 designed from the Model 98 Mauser with an external "cocking" mechanism like a Springfield Model 1903A1. *Ezell, E. C.(1977). Small Arms of the World. 11th Revised Edition, Stackpole Books, Harrisburg, PA 419-420 pp.
If your rifle has a small 1.5 inch (approx) slot milled in the left side of the receiver you have a 1903 MARK I not an A1(I personally have never heard of a 1903A1 I have however heard of the 1903A3as far as value it depends on condition i mean if it has obviously seen combat the value could be as low as 50-100 bucks but if it is in near mint to never been fired condition the value could be upwards of several thousands of dollars and that is just for the riflethe bayonet will also vary in price between $20(i snagged a chromed 1 at an auction for $28) to i would guess a couple hundred