dish

 I have a beautiful old piece of pottery that I have would like to know the maker & value of. It is a very large plate or dish covered with a thick rich brown matte glaze. The front of has a white-grey glaze applied somehow with an intricate feather design carved in it! There is a carved marking on the back under the glaze of a "5 point crown or jesters hat" & the initials "CC" backwords & criss-crossed directly under the crown. It is 15" long, 8 1/2" wide, and is about 1 1/2" tall. There is about a 1/4" chip along outer rim, otherwise it is in excellent condition. I found this in an old house I was cleaning out that was full of antiques so I have no other history on it! I live in Decatur, MI USA.
My research that I did on the marking led me to the pottery co. "NIDERVILLER" from france! I learned that during the General Count Cristine period in the 1700's or so he had his pottery marked this way! I also read that the marking is often mistaken for a different pottery company. My concerns are could it possibly be "NIderviller", is it fake or reproduction, and what is the value?  I am sending a few pics but have plenty more if needed. Any information or direction to someone who could help would be so greatly appreciated! Thank you very much!