Random thoughts: My machine was all there, just in rough shape. Yes I scraped off all loose pieces of paint and rust. There are lots of ways to clean off rust. Maybe I used a wire brush. Maybe some evap-o-rust. Cleaned it with naphtha... I can’t remember what all I did, but no oil. I think I just applied thinned shellac with a rag on my finger. It stuck. The metal was pitted and rough but the shellac filled it in. Shellac is easy to remove if you don’t like the look. Do not use shellac on areas that are moving or will have friction. Some times the worst beat up machines sew the best. Yes look for burrs and bits of rust anywhere along the thread path. If it is shiny metal gone rusty some times I use bike chain oil to remove the rust and then I clean that off. When a machine I have around is so bad it can’t sew some times there are still good parts. Some times I get a machine with too many parts missing. I have combined parts off one on to another to make the better machine run. Some people think you should restore all old machines. It is sure fun to try. If it has too many pieces missing where do those parts you need come from? I do have lots of parts and lots of junk machines.