Gorilla Super Glue is what I had around the house, so that's what I used & clamp it.
The leather works just like if you were to wrap a piece of elec. tape around your thumb but the leather is more of a padding for the thumb with no stickiness.
Check out ken's post below, he gives a number of ideas you could try. I like my thumb to still be like a thumb so, I like the softness of leather vs. something hard in using my thumb to slide. I tried a thumb pick also, didn't like/didn't work