A 17th-18th century Yushman
From the previous owner of this item:
"I "think" the mail/plate hybrid armour dates to c.1650-c.1750 ... though they were no doubt made later. The theta rings almost assuredly place it in an "Indian" (i.e. Pakistan/India) context."
You can see in the close-up pictures of the plates on the back that I have begun cleaning the plates. The scales are alternating materials, steel, brass, and copper.