I purchased a 21-piece luncheon or tea set marked Mandarin and the underglazed stamp (in blue) for Samuel Radford (crown and R with S overlay). It includes 6 tea cups, saucers, dessert plates, sugar (or waste) bowl, creamer and 9" cake or serving plate. It appears to be in near- mint condition. I am wondering what it is worth. Also was there a teapot made in this pattern?