Tundra Labs used to sell strap base plates, but it's been out of stock for forever with no restock in sight, so i took it upon myself to make my own strap base plates!
as for the straps themselves i used old(but clean huh) socks and super glue, a cleaner job could be done with a bit of sewing but i was lazy and it works fine as is.
The author marked this model as their own original creation.