Wiley Horne--So. Calif.
Londonderry Brasses carries this product:
It's expensive. But won't be less so in the UK, where you may also find some.
I have had occasion to order from Londonderry Brasses a couple times (knobs, pulls), and have found Nancy to be extremely helpful and knowledgeable. There are instructions posted at their site as to how to apply the material, and yes, it involves hide glue. You could ask Nancy for more details than what is printed, or perhaps she could direct you to a practitioner--or maybe Warren has done it, better yet--because it's too expensive to experiment and learn by trial and error.