Nice work, Dave. I especially like the re-purposed coins. Did you seal the antiquing? Just asking, because when I first used it, I didn't read the bottle and didn't notice it was water soluble. Maybe I'm the only serial label ignorer around.
Also, I think your stamps would work better if you case the leather. You get it wet on both sides (people vary on how much), roll it up, pop it in a bag, and let it sit overnight in the 'fridge. Next day pull it out and let it dry until it's still cold, but has returned pretty much to the normal color of the leather. You'll be amazed at the better impression you get with the stamp. Also, it helps to have a marble slab to stamp on. People get them from marble cabinet makers for practically free.
Anyway, nice, and congrats on coming up with your own design. That's something that will help you out a lot in leatherworking.