Looking at your machine, it can be hard to tell the difference between rust and dried up old oil from here. The rust will be gritty and the dried oil will have some gum feel to it. I would try to clean off oil on that machine with naphtha or denatured alcohol. If it is rust, get some evap-o-rust or vinegar and remove what bits you can and soak in that. Either one is good to have on hand. You do not want to put evap-o-rust on the whole machine. You can never get it all out of the cracks and corners. Bike chain oil can be used but you will want to get it off with the alcohol. Then you will need a thin oil.