Part Needed. My parents bought a used microwave (Goldstar Microwave MA 1417W) and it's missing the

Question

My parents bought a used microwave (Goldstar Microwave MA 1417W) and it's missing the plastic piece that goes under the glass turntable that makes the glass piece turn. I called the Customer Care number listed on the Goldstar website and in the user's manual (1-800- 243-0000) and it's no longer a Goldstar number. Do you have any idea if and where a one could locate this part?