My wife and I scored 3 great old Victorian pocket doors, complete with the roller hardware. The patent date is 1890, and by the looks of them, they have not been touched since. The hardware was in pretty good condition once I cleaned it up. But the material that rolls on the track wasn't.
Step 1: Roller Material Deteriorated
The material that runs on the track was flat on one side, broken, and generally just falling apart. Good luck finding replacement parts! It finally struck me that a hard poly type of product would do the trick.
Step 2: New Roller Material
So I bought a small cutting board at Wal-Mart. A little bit thicker, but in the end it worked great.
Step 3: Cutting Roller Material
I used two hole saws. 3" for the outer diameter, and then a 1 3/8" to fit the inner shaft on the hardware - well almost. I had to enlarge it slightly with a rotary tool.
Step 4: Cutting Inner Diameter
I used a piece of scrap to clamp the 3" piece down while I cut the inner hole.
Step 5: Clean Up the Material
Between scraping with a knife and using a bench belt sander, I removed all the plastic 'burrs'. Put them all together and they work great.