Follow Glenn's tutorial on the finish. Be very careful to read all his info before you start. I say that first so you don't ruin the machine. In reality you will want to get rust off first- be sure it is rust not dried up oil - they can look alike - I guess it depend on how deep the rust goes. I've mostly dealt with surface rust. I pull off parts that I know I can put back - I don't do the whole machine at one time... Then i soak the parts in something that will remove rust. I have used e-vapo-rust, or vinegar, or citric acid - all work.... I don't try to get the rust off the whole machine by soaking it all at once. I also use a dremmel tool to brush things off. It is amazing how much difference you can make but it will take a lot of time.

The picture is kind of far away but it looks like my Singer 24. If you need a manual I will be glad to send you a copy of the one I have in pdf format. I think there were several different Singer 24 models made and this manual doesn't exactly fit my machine but close. Here is a picture of the one I have

Thanks, BB and MM; mine does look like that. So I am going to study up on the 24 and see what I come up with. Mine is not half as pretty as yours--when I have time to work on it, I'll make some more pictures and show the back of it, etc.