The sights both appear to be homemade (the rear certainly is) and the barrel would seem to have been cut from its' original 30" length. Fortunately, the rear sight looks to have been installed non-invasively, meaning that a more proper sight could be refitted. If that is a US Krag, the barrel band should have NO markings other than a "U" on the right side, at front edge. Below is what an unaltered M1898 rifle should look like. This rifle happens to have a Model 1902 rear sight - other styles also correct, depending on period, but they all have mating handguards and all utilize the same two screw holes.

Front sight:

Hi, Dewman.

The barrel band on that Krag looks like it doesn't belong to that rifle.  Does the other side have what looks like a slotted head screw or is the swivel rivetted on?  Krag rifles have split bands that use a screw to clamp on the single "ear" of the swivel.  The band is held in place by a cross pin in the stock.  The one in your picture looks like it's not split and the swivel has two ears, one on either side of the band.  The cross pin in the stock seems to be missing and the band was just driven on until it was tight.

Edit: Butlersrangers already commented on the barrel band.

Also, it looks like the magazine door hinge pin isn't in all the way.  They can be a pain to re-assemble because you have to squeeze things together while keeping everything aligned.  Maybe somebody with more experience can provide some tricks of the trade for installing that pin.

Could you take a side view picture of the whole rifle and post it?

I do have these pictures.. same quality but different parts