There are several ways that others have used to remove the musty smell of the case. You can put some dryer sheets in it and see if that helps. Also, you could replace the oil pad and see if that helps with the machine. I just love my little FWs and also my 3/4 size Singer 99's. They are really fun machines to use. I also hope your grand children will appreciate your little machines. Are you teaching them how to sew?