Jump in and correct me if I'm wrong, but I think "Pot Metal" is the likely candidate for the casting:
"Pot metal, also known as white metal, die-cast zinc, or monkey metal, is a slang term that refers to alloys that consist of inexpensive, low-melting point metals used to make fast, inexpensive castings. There is no scientific metallurgical standard for pot metal; common metals in pot metal include zinc, lead, copper, tin, magnesium, aluminium, iron, and cadmium. The primary advantage of pot metal is that it is quick and easy to cast. Due to its low melting temperature no sophisticated foundry equipment is needed and specialized molds are not necessary. It is sometimes used to experiment with molds and ideas before using metals of higher quality. Examples of items created from pot metal include toys, furniture fittings, tool parts, electronics components, and automotive parts.
Pot metal can be prone to instability over time, as it has a tendency to bend, distort, crack, shatter, and pit with age. The low boiling point of zinc and the fast cooling of the newly-cast part often allow air bubbles to remain within the cast part, weakening the metal. Many of the components of pot metal are susceptible to corrosion from airborne acids and other contaminants, and the internal corrosion of the metal often causes the decorative plating to flake off. Pot metal is not easily glued, soldered or welded."