Chinese Scale in San Rafael, CA

This is an old Chinese scale presumably used in a Chinese drugstore. I bought it at an antique store when living in Hong Kong in the early 70's, it's age is anyone's guess. Obviously it's seen a great deal of use and has seen better days, as can be seen where the weights wore through the balance on the right side.
It measures 10? high (excluding the original old hanging string) by 7? wide.
It's been hanging on my living room wall almost 40 years and it's now time to part with everything as we are moving out of the country.