Those look like silicone rubber tubing wrapped with leather. The tubing is available in many sizes and wall thicknesses. Looks like they took the tubing, wrapped it with suede leather, glued it down, and cut to length. Some other makers use rubber also for a padding layer.
You could probably find a combination of tubing and leather that would work on your harp. You _will_ have to regulate afterward.
It will wear (as does felt) and go out of regulation, and you’ll still have to regulate when you replace it. Can’t replace felts without regulating also, and you have to have the base off to correct the under/over motion at every regulation, so I don’t really see what one is gaining. A little savings in waiting for glue to dry, maybe. On a Camac, with their cable system, it may make things simpler.