From the blurry details I can make out for your rear sight, it does look like an M1896 rifle sight graduated to 1800 yards. It does need to be removed and flipped around to make it positioned correctly. The hinged action is towards to receiver.

You may find that your rifle shoots quite well. Have it looked over by someone who can check the barrel and receiver and bolt to make sure they are in good shape and get some .30-40 Krag ammo and start blasting away!

Keep us informed. Interesting sporterized rifle but it still is a Krag!