Marked MP with a bird above it? Who? (photo)

I have been searching all day to try to find the makers of this piece of pottery but I do not think I have found it. At first I thought it was MD but because of wear the mark is really MP. It is stamped MP with a little bird (hummingbird?) over it? It seems to be porcelain and have some cracked to its brown glaze. A deer is carved into pattern. I came across names like marblehead mountain pottery etc and none seem to match. Can anyone enlighten me please?