What is the value of a 25-20 J Stevens A and T Co single shot rifle made in Chicopee Falls Mass with an octagonal barrel stamped 5838?

Without knowing the exact overall condition as well as details like matching parts, its pretty hard to say. The low for shot out barrel and bad finish, rough wood, completely functional, all original parts, is in the $300.00 range. if conditions are better, or rare options such as special sights, wood or triggers, then the price would be higher. Rust, pitting,reblue, deep metal wear, changed out or missing sights, junk wood, blacksmith repairs to metal parts, replaced or relined barrel. then the price could go down.