On this Google is your friend. I just did a quick search for Motorhome front curtain track, a bunch of stuff came up.
A couple years back my DW went to a fabric store and was able to purchase some really good material for front curtains. The fabric was a black see thru type that on one side had very small reflective metallic squares attached. This provided a great heat stopping plus we could see out but folks could not see in.
Anyway she ordered new rollers that matched the track, can not remember the mfg but she ordered from Amazon.
07 Meridian 36G
Roadmaster tow dolly
Great Wife!! & Max the Frisbee chasing dog.