Howdy Candace... and welcome to the Forum!

Your dad's Krag is a US Springfield Model 1894 Krag Rifle that has been cut down and sporterized.  The banded front sight is from a model 1903 Springfield.  Redfield is the manufacturer of the rear sight, which is a model 70K (and appears to be missing the eye peep).  The stock is a cut down rifle stock that has had a piece grafted on at the rear to increase it's size.  It's missing the rear barrel band.  This is a very nice useful Krag that should be great for hunting and general plinking.  Nice sporter!