What James said...
To elaborate just a bit with my own two cents, with old bags, from what I have seen, it seems there is a definite group of bags that appear to be made by professionally trained leather workers (saddlers, harness makers, perhaps even cordwainers etc...)...these bags tend to exhibit a degree of uniformity in construction techniques and materials if not actual shape or pattern...and they seem to span the long rifle era...
then there is a second group, they are the "cobbled" examples...these generally seem to be made by someone who knew what they were doing as far as leather work went, but who were improvising as they went with non traditional techniques or quirky individualized methods, perhaps through necissity (lac of tools and materials etc) and very often were using recycled materials, the true sign of a "cobbler"...but in all they were trying to keep to established forms and styles as best they could.
then there is a class of the total "one offs", and they seem to made by some one pretty inexperienced in leather working that just needed or wanted to make a pouch and did so...how ever he could with what ever he had...these show the greatest variety of construction style, and are truly individualistic...some of these are really neat, and some could even be called artistic...however most are just plain utilitarian examples.
So...we have old bags made by professional workers, they use trained techniques, proper tools, and are often using established patterns, and high grade materials. Thats what youd expect from a pro...he has the tools, the training, the experience and the materials at hand to make a living at his trade...
And old bags made by itinerant workman, or "jacks of all trades" that cobbled what they could as best they could...note, often bags made by professional makers exhibit repairs done by this group of workers...and I expect this group included farmers and workers skilled in other various trades...
And finally, we have old bags made by the artistic individualistic anything goes makers....
In general, it seems that examples of old pouch making will tend to fall into one of these catagories, and now most examples of contemporary pouch making do too...and curiously, perhaps for many of the same reasons? ie...training, availability of tools and materials, and necissity...?
So to come full circle, What James said...
TC