Small Chinese porcelain dish that was a wedding gift

by Magali
(South Florida USA)

In 1966, my mother-in-law gave me a small porcelain dish (6.5" in diameter) on my wedding day 47 years ago. She told me that my father-in-law had bought it from a wreck diver during one of his business trips to Hong Kong and given it to her. She added "This is a Ming Dynasty porcelain". I've had it on display in my living room all these years, but now that I am retired, I need to have this piece authenticated so that I can auction it off or sell it. The dish still shows some glaze, in spite of having been under the China Sea for centuries. The under-side of the dish shows the rough place where it was attached to and extricated from an underwater rock by a diver (see photos). How can I obtain a certificate of authentication? Thanks