Would RV manufacturer have extra accessories for purchase?

Craigslist. Lot of retired folks that still know how to sew and offer their services for a reasonable price. Some of the old fashion cleaners will have a seamstress on board also. At least that way you can pick out the material you want and the size.

That's what I did. I found a retired lady that sewed me up some curtains for the cab over in my first Class C and she did a very professional job.