Did a quick DTO (at least of the pose) of one of the four classiest posters here (upr_crust, clarinetplayer, Holdfast, and of course you, dear reader)
Pants are Wolf vs Goat. @Mauro has done a couple of pairs that are very MC friendly and obscenely well made.
Details on pants. Worth clicking for a close up of the fabric alone. (Click to show)
A good deal of handwork, canvassed waistband. Just really, really good pants. I cannot recommend these enough.