Have you thought of making one?
I'm serious! I used two types of leather black leather. Both were scrapes donated. One was a ridged thicker leather for the back and flap and the other was a soft garment leather for the sides and lining. I used an old fur collar for the fur and an old earring of my mother-in-law's to decorate the flap. I made a leather knot button and a loop to close it.
I made an American simi-formal. (Yes, I've been told they don't do that in Scotland).
It really wasn't that difficult. It was time consuming and I did splurge and get a stitch punch so I could get the stitched holes even but I double stitched the entire thing with black sinew. I even made my own tassels and beaded them with silver beads at the head of each tassel.
My husband loves it but he doesn't even own a kilt yet! He wears it with his tunic and shirt I made him for Ren Fest. His tunic has a black leather rampant lion on the front and Celtic knot work up the insets of his sleeves of his shirt.