[Arran]

Mike;
The one I found in the Stromberg was made like a small automotive belt, it had bands of cloth laminated to the rubber, presumably to prevent stretching. Leather would be preferable, if it would fit, as long as the leather is conditioned from time to time it would outlive the rubber ones, at least the natural rubber ones, polyurethane might hold up long as well, a lot of synthetic rubber is what is called "butyl" rubber, which is what they use in tires, it gets hard with age.
Regards
Arran