I have finished the mountainman knife and it's sheath sooner than I expected. The sheath is a bit of an experiment in that I have made it to include the firesteel and the knife in a one piece sheath. The knife fits in the sheath at an angle to try and keep the overall size reasonably small. I think it works quite well. I am not so keen on the twisted leather loop I used, although this is more of an aesthetic thing: the loop is plenty strong enough, works well and many scandinavian sheaths used twisted leather loops like this one.
I have also made a brass plate and loop which is riveted and glued to the antler handle. This will accomodate a leather wrist strap.