I agree with Kevin as to matching condition. I would leave the hangers attached. Unless they have a great amount of wear, they will not "wear out." What wears the straps and the clips is the dagger swinging when worn, which, of course, is not happening when displayed while laying flat or even hanging on the wall. It takes a substantial amount of wear for there to be adverse effects on the hangers. Even then, the straps would likely show the most damage. The clips and scabbard rings wear well over time.