I have one just like Stumpy's that works great, but I'll be darned if I could find one for sale anymore when I looked online before responding to this question.
However, if one wants to attach the back to the wrist vs the butt, the long strap of leather with a slit in each end would work just fine. Just feed the strap into the slit on each end to form a loop and slide one to the wrist and tighten and one over the barrel. Just make sure to make it out of thinner very pliable leather.
No matter what you get, be careful about any design that puts too much "bulk" on top of the barrel. I have several versions and a couple of them are thick enough that they can shift a bit during use or loosen a bit and lift up and block the front sight.