Felt Solution

All the dithering about whether to use black cotton or black and white striped cotton on BronzeAge came to an end when it dawned on me that I could probably needlefelt black felt pieces to the background fabrics, and then they would be securely attached and there'd be no fraying and I wouldn't have to quilt over the edges to keep them in place, which I'd also been worrying about because black thread would show too much on the reddish background and red thread over black elements might look like a design element of its own instead of fading into the background as I wanted it to. I love this solution; it's elegant, in the way that a three-line, mind-illuminating mathematical proof is elegant.

Now all I have to do is find the black batting, pick a backing fabric, put the sandwich together and quilt it. (This is the stage where I wish the Quilt Elves would come in at night and finish the job.)

Oh - and binding. I think I'm going to use the black and white striped fabric for a binding.

And,possibly, artifacts. I'm thinking about adding some little wire coils and polymer clay "potsherds" and other doodads to the quilted surface, as if they were objects found on an archaeological dig.