Well, this was interesting, wwh: I read through some definitions of durance and one was synonymous with 'imprisonment,' as you wrote more specifically with your 'durance vile,' although apparently you don't need to append the 'vile'...


...and the third definition being obsolete, but I wonder? There seems to be a very popular fabric here in the South, and probably many other places, too, that meets this description:

"an obsolete strong felted cloth of woolen or worsted usually made in imitation of buff leather "

We do have a fabric that appears to be buff leather that s actually a kind of felted cloth. It looks very much like moleskin. If of troy happens by here, she may know the difference.