Antique Coffee or Tea Pot

Silverplated coffee or teapot with a flower motif, two inlaid bone or ivory rings in the handle. It is six inches high and six inches wide.  On the bottom, it has several small stamps I was able to  photograph which seem British. I have not polished it at all, so it's pretty black. I'm thinking the best way to clean it would be to immerse it in a commercial preparation that hotels use. The home remedy of aluminum foil, detergent and salt apparently strips the silverplate. The wingnut tht holds the decorative rose to the top seems to be an original part of the piece, but I imagine indicates it's not a truly valuable piece. I am curious as to how much I could sell this item for. I received it free. It came from a family on Maui.