The Fjestad Blue Book has a couple of .25 caliber Stevens rifles. The TIP-UP RIFLE, which matches the years of manufacture, is the most valueable -- but came in 15 different styles.
The very best, in pristine condition, might be worth $400. If its in rough conidition, irs probably worth $100, or so. Only really CHOICE guns are generally sought by collectors.
You need to take some pictures and post them here, if you can.
You might check with Cherry's in Greensboro, NC -- they specialize in collectible weapons -- with examples, etc. on their website.
(WWW.CHERRYS.COM)