By referencing the surviving artifact pool of Period "bowie" style knives- in brief and to over generalize...
You will find two basic routes to explore.
The first are the professional and commercial made "bowies" made by American and British cutlery firms. For example, the Sheffield England knife industry. These tend to be finer examples, and their scabbards or sheaths tend to have metal fittings such as metal throats and tips. Often the throats have studs that went in a sliding belt frog.
The second group are more so-called "primitive" bowie knives made by local knifesmiths, blacksmiths, and for the 1861-1862 Confederate short sword/bowie knife (and D-guard) fad even by some Confederate arsenals.
Among this group, and perhaps more illustrative of the short sword "bowie" replica you have, there are three basic "styles" or forms of sheaths:
1. Those with a belt loop that extends above the throat of the two piece or folded over one piece sheath.
2. Those with a belt tab sewn to the back of the two piece of folded over sheath below the throat line.
3. Those where the back piece of the two piece sheath extends above the throat line and has two narrow cut-out slots for a waistbelt to pass through.
In gleichem Schritt und Tritt, Curt Schmidt
Not a real Civil War reenactor, I only portray one on boards and fora.
I do not portray a Civil War soldier, I merely interpret one.