China belt vintage ( silver or not silver?)

[mysterling]

Hello everyone and I hope I do not miss the forum section.
I found this old Chinese belt. I tested with acid for 800 silver but it gives me a strange answer. Could it be inferior silver?
I thank anyone who can give me information about the hallmarks.

[mysterling]

I don't know if only me dont see the images, but have been inserted with the correct TAGs.