50-500 depending on specifics.
If it's in .30-06, you'll see a reduction in value, as the Modelo 1909 was chambered in 7.65x54, not .30-06. Probably $100-$200.
270 mauser modelo argentino deutsche waffen-und munitionsfabriken a2608 berlin B
No sn data published I know of.
Unaware of any published sn data.
what is the value for an American 1909 silver dime
The value of historical items like this depends very much on the auction market and demand and interest--to say nothing of the condition of the particular item in question. You cannot t really say what a C96 Mauser is worth generally; you can only guess what a specific C96 Mauser might be worth if it came up for sale at auction. Your question can't really be answered other than to say that you explore eBay or other auction Web sites for items in similar condition and see what people are paying for similar items.
What is the value of a 1909 Remington 25-20
German Sociological Association was created in 1909.
Not knowing how many variations of the Chilean Mauser were made, or which variation you're referring to, the assumption will be made that you refer to the Mod. 1908, which was a variation of the German Gewehr 98 Mauser. This stock, and stocks of other variants (such as the Argentine Modelo 1909) should have some degree of interchangeability with the Mod 1908, although it is possible that some sanding or other minor alteration will be necessary.
That'll be dependent on condition, whether the serial numbers are all matched, what accessories come with the rifle, etc. You're best to have this appraised by a dealer whose specialty is C&R firearms.
No SN data published. Year of manufacture should be engraved on the crown.