Matt,
The sheaths were only shown in the 2009 catalog. Those would be tang stamped with a right pointing arrowhead after the model number 301. As Plumb says the new version the next year with more pocket friendly corners did not have sheaths shown in the catalog.
Which brings up your last question and one that we have discussed on several threads in the past. How you carry your Buck pocketknife? "In the beginning" pocket knives were just that, knives in the pocket. Somewhere on your person, in a pants pocket, or in a vest, on your bibs or even a jacket, you would carry your knife. In the more recent of times as the use of tighter fitting clothing came into vogue, the bulge of the knife in your front pocket became unpopular. All manner of belt and pocket sheaths were created to deal with this. Or, as in even more recent times, the return of 'baggy' or loose fitting clothing has allowed front pocket carry once again.
Do a forum search for threads with sheath in the title and you will find all manner of designs. I favor a small leather sheath for my 301 that hangs on a cord or "leash", as I call it, from my belt down inside my front pocket seam. Some have fashioned back pocket sheaths for their favorite mode or they use a small belt sheathl, which improves access when bending or squatting. Good Luck.
300Bucks