I'm using very thin leather scraps from cheap coats picked up over the years at thrift stores as the base of the medallion. The suede side won't show through the beadwork and the back of the medallion will be covered with a nicer leather. Sewing the beads and braid border on the scrap, I'll then attach the backing by sewing through the horsehair braid. Picked up a good bit of brain tanned leather thong in October and will using some for the ties. It is so soft and durable.
Using the 11/0 beads, I haven't had needle problems yet. My weaving/lunch break is over. It's coming along.