Can't say for sure on type of metal , but it is heavily oxidized as you can see. However , I just checked it with a heavy magnet , and it has no magnetic properties what so ever. Upon looking at it closely , the remaining color seems to be more like enamel. It has no "glimmer" to it as metal plating would have. It seems to have been a white background , but has ambered with red soil and dirt over the years. Whatever , the coating , it is in perilous condition , and even with moderate handling tends to shed some flakes.
With the oxidation , and non-magnetic properties , I would venture that it is a pot metal.
But all readers please do this for me , and check to see if my mind is causing me to see things that are not there. When you look at the reverese of the object , see if you see any distinct features or shapes come to the forefront of your eye. If so , please feel free to highlight them , and repost , and let's see if you're seeing what I see.
Thanks in advance.