There are a number of different makers of Thermo-Form (Kydex and Concealex) sheaths for the Mule Team knives.
Mike Sastre of River City Sheaths http://www.rivercitysheaths.com/
You can see images of the work Mike does, in the article by Mr Blonde from the Spyderco Forums, on his site http://www.spydercollector.nl
http://www.spydercollector.nl/index1.php?pagina=&id=224&ex=review#article
And there is also a thread that Mike started at the Spyderco.com Forums that shows images of his sheath.... http://spyderco.com/forums/showthread.php?t=36160
Scott Gere of Scott Sheaths http://tonybakerknives.com/sheaths.html
There are a number of different threads that show Scott's Mule Sheaths.....
The first three images in this post, are of sheath made by Scott... http://spyderco.com/forums/showpost.php?p=510750&postcount=3
And all the sheath images in this thread, are of Scott's work... http://spyderco.com/forums/showthread.php?t=32308&highlight=mule&page=2
And both the sheath and scales of this knife were made by Scott... http://spyderco.com/forums/showthread.php?t=32308&highlight=mule&page=2
Marion David Poff, I also makes Boltaron/Concealex Sheaths for the Mule Team knives. Marion Carry
Thank you,
Marion marion.poff@gmail.com