Well CAgem and I went out and gave it our best shot. I think the coin is a British Half Penny, an odd find in California but my favorite is the lead toy soldier.
I'm trying to clean it but it may be a lost cause. I've done the peroxide until it quit working and now I am just soaking it in olive oil. There's a lot of mineralization stuck to it and I don't want to wreck it. When I took it out today and scrubbed on it a bit with the brass brush, it did improve so I may have to soak it for a long time. I've had good luck using this method with my ancients, so we'll see how it goes. If all else fails, I'll get out the Dremmel.