A paradox is rifled. A gun with paradox serial numbering with no rifling most certainly has been altered. True ball guns seem to be rare. I think this gun was at Caswell's for a time and he believed it to be original. I know what you mean about the locks but on the early rounded hammer guns they may be straight. I have an early 12 Holland rife and the locks are straight. I don't know of another early 8 to compare it to.