I have a fellow co-worker that has a perc. rifle with little history that we can find anyways. It was made by Mowery Rifle Works and is a copy of a Hopkins Allen rifle. Its a .54 caliber with adjustable trigger and maple tiger strip stock. His questions are: What is it worth? , can the lock be replaced if needed also the barrel? Its a nice gun, oh and also it is the rustic brown finish. Anyone have one or know anything. Thanks.