If you end up not being able to get the fit to your liking around the mouth another option would be to add a nylon strap and button, espcially since the sheath is in 2 pieces still. Snap setter kits are leativley inexpensive, like $15 with snaps. You could use a rivet or Chicago screw to retain the other end of the nylon strap. Good luck and let us know how it turns out. Nice DF by the way. I missed the first round.