Sherian,
Did you go to the Singer site and download the 353 parts list?
http://parts.singerco.com/CPpartChar...99/353_354.pdf
If it's the right one, I don't know about your machine, it will give you an idea of what's inside. And Candace is right, a hardware store, or a sewing machine shop. Crimeny, don't give up on the machine due to one lil screw.
Joe