I have a Featherweight and by the serial number was born in 1939. It is in excellent condition but I am going to sell it this summer and I need help with the musty odor. I have a dish of vanilla sitting in the box with the attachments. I took the bottom off the sewing machine and it looks like rubber in the metal piece. It is so tight in there I would have to scrap it out. Just touching the rubber oil comes off on my hands. From what I have read it is supposed to be something like felt that is holding the smell and could be replaced. Now what do I do?