Nice plate!!
Can you give it's measurements, which will help in determining which belt plate it is?
But I must ask, why is it so shiny?
It looks like you polished it and that unfortunately will decease to value, IMHO, most collectors want to see the original patina.
I would bet that it's a recent loss. Maybe a re-enactor's piece?
I would bet that it's a recent loss. Maybe a re-enactor's piece?