Slightly off topic here but worth mentioning…
Wasn’t there a lack of clarity surrounding the actual weight of selvedge denim? I understand this is based on the fact that denim and other fabrics are (or were) generally attributed weight by the square yard, ie 12oz was theoretically the weight of a square yard of denim (pre-wash).
However, I’ve heard the quoted weights for early Levi’s jeans were based upon a yard of fabric length, which would only have been approx 30” wide (from a shuttle loom) and therefore less than a square yard and consequently lighter. This may be why some of the early pairs (late 18th/early 19th centuries) were (possibly mis-) quoted as 9-10oz, whereas in reality, miners would have required something heavier and more resilient, perhaps more akin to the 12oz denim of the 40s pairs. By this possible miscalculation, a 10oz yard of denim was only 5/6th of a square yard (36” x 30”) and would actually equate to a 12oz square yard.
Hopefully someone with more knowledge can confirm or deny.