jdallagranda:  You have inherited a Model 1899 U.S. Krag Cavalry Carbine that was produced at Springfield Armory in September, 1900.  The 1899 Model was strictly a carbine.  The Redfield sight was 'After-market', but fortunately did not require any holes to be drilled into the Krag receiver.  This Redfield ('No-drill') sight is held on by a special longer side-plate screw.  (The screw in peep is common).  The Redfield #102 sight and its screw are worth around $100.  To restore your carbine, you would need a correct side-plate screw and magazine cut-off.  (These parts were removed to mount the #102 Redfield sight).  It appears the correct Krag sight for your carbine and its hand-guard is the 1896 rear sight.  The 1896 Carbine sight is in great demand and loose ones routinely sell for $400 to $500.  The 1896 Rifle sight looks the same, except for markings, and can be found for around $35.  The biggest problem for restoration is that rubber butt-plate.  It appears the stock butt was shortened to give a flat surface for the rubber pad.  Krag butt-plates are not hard to find but they have a bit of 're-curve' at the toe and the wood stock butt is curved to accommodate this.  For insurance purposes, I would estimate your Krag worth $700.