new pattern dial toyota rs2000-2d sewing machine?

where could I buy a replacement pattern dia for my Toyota RS2000-2D SEWING MACHINEl. My daughter used excessive forse when selecting a stitch and has actually split the plastic casing so the metal part inside becomes dislodged. I can manage to turn the inside part with pliers in order to change the stich. Have looked thro lists of spares online and this part does not seem to be available. Can you help?