Small pot, possibly American?

Does anyone have any ideas about this one, purchased in a charity shop, the shape and design make me think American, possibly based on traditional native American/Mexican pieces. The front design is partially raised with a sand like texture, the base has a written monogram NP 38, possibly MP, I presume the 38 refers to the year it was made; the only NP I can find is the Nemadji Pottery but they seem to have used an ink stamp.

Paul

Yes, I think Native American or Mexican pottery. The decoration looks a bit too Westernised for traditional wares from one of the Reservations.