1871 Argentine EN Mauser

I am looking to buy an 1871 Argentinian EN Steyr Mauser long rifle serial 66030 in 11.1 manufactured in 1875, it has an unsanded stock and all metal is in unpolished white with nice patina and toned aging spots. The seller wants 1399.00, I am thinking 900.00, WHAT DO YOU THINK. According to the seller the bore is in excellent condition ,smooth, bright , strong rifling with just a couple small opaque spots.*The only mismatched part is the bolt stop screw and I need to know what parts of the gun were originally blued. To me if the barrel was blued originally and the bolt face showes very little use then WHY IS ALL THE BLUING GONE. One last note,* the trigger guard is brass.

I have a very small sample to go by, and mine is Uruguyan...My trigger guard is brass. Mine was converted to a smokeless cartridge for Uruguay in 1894. It is all blued. Since I have had this (couple years) I have been researching all I can find about it. Some I have seen are "In the white", some are blued like mine.
You can search on Gunbroker, and look at others... There are videos on the "Dovitiis" Mausers.
Sorry I am not more help.