Well two Indian heads and a 18th century shoe buckle would make most of us very happy for a hunt. Always makes you wonder when you get almost a hundred year span between the finds, which is good sometimes, it means a long occupation of the site, but could also indicate the IH's were lost by a hunter/logger/or whatever. I would soak that buckle in warm distilled water for awhile to try and neutralize those copper salts and dry thoroughly and then coat with something to protect the metal from air.