Japanese Teapot

This is a beautiful tea set, which has a teapot, sugar bowl & creamer, 6 cups, 4 ea 4" saucers & 4 ea 6" serving plates. The marking on the bottom is a rectanguar box with a gold border and image is all in gold on a dark red or maroon background. I'm told that the cross in a circle is the Shimazu family crest, gut I don't know what the rest of it is. At this point, I want to establish an identification and an appraisal. I'm including a sketch of the marking alongside one of the creamer. Thanks. Bob