Nice! It always amazes me how coins do or don't migrate based on the local conditions.
At one wooded site I hunt a lot, I've found probably close to 100 shotgun shell heads lying on or just under the surface. I figured that they were modern(ish) junk until I looked closer and started dating them. None were newer than the 1930s and the vast majority were 1870s - 1920s. I've pulled quite a number of Indian Head pennies scattered across the same site, and none have ever been more than a couple of inches down, including one dated 1865 from which had to simply brush some dirt away to retreive it. Crazy.
Then there's one area I know should have coins and jewelry, but I don't think I'm getting deep enough. The first six to ten inches are all soft humus and roots, and below that is sand, where the good stuff should be. Too much scraggly brush to break out my big WOT...