Gutta Percha, Bakelite and shops Celluloid Necklace

Product Name: Gutta Percha, Bakelite and shops Celluloid Necklace
This necklace has me stymied. Done in the style of memento mori, it appears to be an older, 1910s-1920s manufacture. The chain is lightweight, molded celluloid whose links show seams across the circles, but all seams are sealed shut. The plaque, which is hand-carved, tested positive for Bakelite. The cameo has the rough, odd feel of gutta percha. In decent condition, someone reglued the gutta percha cameo back onto the plaque, and the gutta percha is a bit warped. Expect some glue there. See photos. Necklace measures 26" by 3/8" wide. 2 1/4" by 1 7/8" shops. Weighs a very lightweight 1 1/2 oz.