chele, The silver disc on the back is for servicing the machine. you can release the disc and oil the moving parts, anywhere that 2 pieces meet and move. You can pick up a belt at Joanns on the notions wall or go to a good sewing machine dealer for a complete rehab. If you do this yourself, DO NOT use any heavy duty cleaners on the outside of the machine. Try a little Dawn in a bowl of water and a wrung out rag or paper towel, and wipe down the machine. then dry off. If you use chemicals, they will remove the pretty paint. So glad that you found such a little gem.