I have made seven of these and worked on getting my Leathercraft from 0 to 41 in three days when I was online at the time. Anyway, my Goldsmithing skill was at 80 when I started to make these on Fireday and during a few synths, I got Leathercraft skill-ups at the same time while getting a couple Goldsmithing skill-ups. Based on what I've experienced, Leathercraft around 35-40 would be the subcraft skill probably needed to make these at least.