I just cleaned and oiled my Touch and Sew 648 that I was given......used to be my aunts. If you have the book for it it shows you exactlywhat to do. It's a nice machine.
I have the Singer Creative Touch 1030 and it is still a workhorse. I love the old Singers.......I have my mom's still at Dad's that I need to work on the tension all of a sudden.......it was made in 1952. I intend to pull the book and work on it when I get back up there.