I have been given an answer to this mysterious pc. I have been told that this is a #351 Priscilla pattern mustard bottom made by Heisey with an unknown cutting. The color however was achieved by a strong bombardment of Ultraviolet radiation, beyond what the sun will do. Serious Heisey collectors consider the piece destroyed since the color was achieved artifically. There have been threads here before about sun purpling of glass and here we have an example of man made sun purpling so to speak. Terry