I would agree with
@Capt. Jas. regarding the buckle on the back, for all the reasons he listed.
I've been researching old pouches in my limited way, basically studying images of antiques found online. The ovewhelming majority of the pouches I've found pictured had no adjustment in the strap at all. Most of the pouches that appear to have been made by professional cordwainers or saddlers have the strap stitched in place (a lot more could be said about that...), while pouches with native provenance have the strap simply tied on the pouch with a tangle of buckskin thongs. This Dakota pouch from the Minnesota Historical Society is pretty typical:
Tied on with thongs that way, the strap could be adjusted by shortening or lengthening the strings, or by punching additional holes in the strap. To our modern eyes, this may not look very secure, but they would not have done it this way if it didn't work. This one is from Milton Von Damm's book about fur trade artifacts:
That strap is a mess, yet the whole rig is still more or less intact. I don't know if this next one is native or not. I found it on the Cowan's auction site:
Again, the strap is just tied on with thongs. Maybe a replacement? Maybe not...?
I think this next pouch is really cool. I believe it was on the iCollector website:
The position of the horn tells us that this pouch was carried on the right side. That would place the buckle in front. However, check out the pouch on the right, in the following photo, from the Poulin Spring 2022 Auction:
That is a pretty fancy pouch, and one of the relatively few originals with a leather tabbed webbing strap, so they did exist. Again, the position of the horn tells us this rig is set up for right-side carry, which would put the buckle on the
back. The pouch on the left has a skinny, nonadjustable strap, nor do I see a buckle on the pouch at top center.
Finally, if you are really undecided, there is historical precedent for buckles on both the front and back. This South Carolina rig is in the MESDA collection:
Lots of options...
Best regards,
Notchy Bob