Here are 3 keychains from the Sega Fan Club. It's the back-card that reveals where the "aged metal" keychain objects seen around these pages are all likely from. The first one is the Segasonic logo in a ring, done in copper with dark enamel in the low spots/textured areas. The middle is a pewter-tone bookmark-looking one with running Tails in a disk & the last is a large flat copper/dark enamel with raised/relief leaping Sonic. As you can see here, they came in little clear plastic sleeve-bags with simple back cards.