I get 20 Mule Team at the local supermarket, I thought it was still a common product.
I soaked some bufflar hide for moc soles and stretched, here's some pics how I do it. Just like I do green beaver hides to sale only I used smaller nails on the buff hide.
I start in the middle of each side and stretch the other side and tack, driving the nails in angled outward. Get all four middle edges stretched and tack about 1" all around the edges.
I use a screw driver to pry the hide up the nails to raise off the board and let air circulate underneath. Sometimes I use a fan to speed things up.