New vintage silver Indigenous head headdress pendant charm necklace (Montréal)

New vintage silver Indigenous head / headdress pendant charm necklace (Montréal) Special find! North American Indigenous Aboriginal/ First Nations Chief head in headdress. Probably white eagle feathers. 18x8 mm x 3 mm deep Detailed cast. Heavy! Nice patina contrasting. Can’t find a hallmark! But I took lots of pictures! I believe it’s silver! 16” fine sterling silver box chain, almost 1 mm wide Hallmark on chain: “GDR” + “STG” New vintage c. 1970s. I thought GDR: meant German Democratic Republic or East Germany (c. Post-WWII - 1990 unification). But it is from a Montreal jeweller who came once a year with beautiful gold and silver.