I have several pieces of a tea set with the mark "Davenport." The set includes several sizes of teacups and saucers, a teapot, creamer, cereal bowl and sugar bowl. I would like to know the value of it. I also have several other cups and saucers marked with a crowned "N", "Royal Chelsea", "Foley", and "Victoria Carlsbad". Can anyone provide me with the history of these items and their worth.