They have no magnetic properties and the weight seems heavy for their size. But I can also see silver spots. Most of the casting like the figures are heavier then aluminum.
The window and shadow box may be a aluminum alloy? JAKE KOSER has historical metal work of President Lincoln in the Indiana State Museum. This American artist specialized in engravings and metal work of historical figures, he also did a lot of work from the civil war era. JAKE KOSER was BORNED 1900 and passed in 1975.