Magnesium hey?
excuse my cynicism, but you know that the magnesium version of TE37s are around twice the price of the standard forged aluminium TE37s?
don't be offended, but i don't think yours will be magnesium - they'll be conventional gravity cast alloy.
don't believe everything you're told, or even what it says in the casting! Taiwanese and China manufactuers will cast anything into the wheels...