Very nice! 

It appears to be re-blued, and the bolt appears to have been polished.  Dean is correct about the rear sight being a 1901.  The sight may have been installed in an arsenal rebuild, but it also may have been the original sight if the rifle was built in 1901 or later.  The serial number and cartouche will tell you when the rifle was originally built.  I see in the pictures that the cartouche is nice...  I assume that it has the proof mark intact also (located behind the trigger guard on the bottom of the stock)? 

How is the bore?  You may want to have the barrel slugged to determine what size bullet to use if you plan on reloading for cast bullets.  Otherwise, you should have no problems firing factory Remington or Winchester ammo, which is available.  You can find those is some sporting goods stores like Bass Pro or Cabelas.  You may also find them for a lower price on web sites like Cheap as Dirt.  A word of advice... Save Your Brass!!!  If you reload (or even if you don't), due to the cost of 30-40 Krag ammo, you may consider reloading in the future.

Welcome to the site and to the wonderful world of Krag rifles!!!