Milestone single hung overhaul

I need approximately 4 channel balances (28B) for Milestone Single Hung Series 1000.

6 balance stoppers, or whatever they're called. It's the white cap piece at the top of the operable window that keeps the balance hidden from sight. There is one on each side of the window, and they're attached with 2 screws. Approximately 15/16 wide and 1 1/2 long.

Also, several interior beauty covers are cracked. It looks like the window was open, the lock was engaged and then the window was slammed shut. Thus, cracking the covers. I need a few of those. Can they be purchased in linear feet, and I can cut to size?

See photos.

Thanks,
Schuyler