The tubing that is commonly sold by the player piano companies was
known in the tubing trade as Santoprene tubing.  You might search
for it on the 'Net.  McMaster Carr has sizes up to 1 inch.

I have never found a source for the twill covered tubing and I wonder
where it is used in industry applications.  Maybe marine?

Don Teach - Shreveport Music
Shreveport, Louisiana