Ashtray or pocket emptier signed JP-MD numbered 12

Art Deco cup or ashtray with naked woman lying on one side, signed jp - md number 12, artist from the end of the 19th century (pierre jules mener), I think the object is made of plaster but it is relatively heavy, dimensions approximately 18x13x6 cm, no defects, just need cleaning because I just put it in soapy water after a long stay in a garage!