Oh, I thought you said it does not have the slight sheen. I was commenting that there is a fabric that exists and is not too hard to find that does have the sheen, and you don't have to spray it with anything. I guess if you already found the fabric with the sheen and it's the right type of weave and right color, then that's good.
Isn't automotive headliner hot and doesn't it not breathe well? It always looked....somehow rubbery to me. And can you dry it in a dryer? I'd be sure of those things before I used in in my costume. It also seems as though it will not quilt right across the vest sleeves. It's too puffy.
Side note: There are different types of batting, and I would not use the 100% cotton kind...it's for quilts, and will give a crinkly appearance once washed.