I don't know if you'll have much luck finding a kydex sheath maker with an in-house NWA Sierra Scout. The odds are you'll have to the send the knife in.
If you are willing to send the knife in, I can recommend both Mike Billman of Grindstone Cutlery and Kiah Stinson of Kiahdex Sheath Systems. Kiah has a subforum here you can check out. Mike Billman made this sheath for my Scout, and I love it:
Kiah does excellent work as well, and while I usually get stacked/pancake sheaths from him, I'm sure he could put together a nice fold-over for you.