i saw something like this in my lucky magazine & was really excited to make one for myself. i had an old sterling silver ring base lying around that worked perfectly. i'm pretty sure that you could use a more standard ring base as well. the leather buttons i had were a bit off in size, so i lined & glued a bit of hot pink binding tape around the edge (which is not as noticeable in person). i then used needle nosed pliers to pull the metal button hook from the back of the woven leather button & secured it with super glue to the ring base. it's a little loose still - i may have to find a stronger adhesive. i just love it though.
my pinkie really is that crooked.