Very nice sporter there...  I can tell you that it's an 1898 model...  Some of the other, more senior members can probably tell you more about it than I can.  It's probably cutdown from a full rifle length.  With the bolt closed, drop a cleaning rod down the bore to measure the barrel length.  A full length rifle barrel should be 30 inches.  Most cutdowns are 22 or 24 inches.  That should be a nice shooting rifle either way...  Why do you want to sell it???