New vintage silver Pharaoh / Sarcophagus mask head pendant necklace (Montréal)

New vintage silver Pharaoh / Sarcophagus mask head pendant necklace (Montréal) Egyptian symbols especially gold Nefertiti heads were very popular in the 1970s! 18x12 mm x5 deep Pharaoh / Sarcophagus mask. Detailed cast. Heavy! Nice patina contrasting. 16” fine silver box chain, almost 1 mm wide (Mithril-like) New vintage c. 1970s. Made in Canada - Montréal. Hallmark on chain: “GDR” + “STG”. There are marks on the pharaoh but I can’t make them out. I previously thought the GDR hallmark meant German Democratic Republic or East Germany (c. Post-WWII - 1990 unification). But it is from a Montreal jeweller/gold and silver smith who came once a year with beautiful genuine gold and silver.