I just got a response from Norman at Windslyce:

1. Original balls on Bim2000s are Torlon 1/4inch-- likely all manufacturers (Harkan, etc) are sourcing balls from the same supplier.
2. They now use a patented since white lubricating teflon ball in the system to improve performance.
3. Regular maintenance should be: plastic pot scrubber on the track, make sure balls are wet and moving before sailing (no hard salt crystals so even salt water rinsing is ok), and NEVER use WD40
4. If you, like us, have a fleet of A-class boats, it is possible to buy a tool to replace balls faster and easier (although I hate to miss the opportunity to find new uses for KY jelly).

Overall great response from Windslyce-- so I will probably get all parts from them. And thanks to everyone on the forum.