Here's the buttons glued on, showing them before and after painting with the Rub-n-Buff. The buttons are just cheap plastic ones. I had to sand them a little on the back to make sure the glue would hold.
And here they are stitched six inches apart on the belt. The upholstery tacks have not been put on yet, but they will cover the stitching and holes so that it's not obvious that I've used buttons.
I really hope the decorative tacks are convincing in making these decorations look more appropriate. I was so happy while I was busy gluing everything and painting -- it wasn't until afterwards that I looked at these things and thought : Bottlecaps. It looks like I've put bottlecaps on my belt.
I found some filigree bits in the scrapbooking section at the craft store as well, and they will fill the interstices between the doodads, and also hopefully help with the illusion of medieval metal-mongery.
It'll look great when I'm done, I just know it. It's just going through an awkward phase right now. Stay tuned!