Assuming you're willing to go the distance (and spend the $$$) to restore this machine, you'll need to get Evaporust to soak the rusted parts in.
That being said, I'm one of those Craigslist junkies that hunts down every machine in my area worth repairing--and based on this photo, I'd pass on this machine. I'm not saying that to be discouraging or to dissuade you, just want to share what I've learned the hard way in the hopes of saving you some trouble and $$$, or preparing you for what's to come if you decide to take the plunge:
We can see in the photo that the bobbin area is pretty badly rusted. You'll need to take all of that apart in order to get the rust off, and even then, there's no guarantee it won't be pitted. If it is, you'll need to purchase those parts.
Ditto for the bobbin winding mechanism, and with that amount of rust--or "oxidation," as some like to politely call it--I'd wager the spring is bad as well and will need to be replaced along with the rest of it, unless the Evaporust does the trick. (The bear is, you won't know until you try whether it will work or not.)
The needlebar area and the one tension plate left on the machine also shows rust, as does the thumbscrew holding the faceplate on and the thread guide that's north of the tension assembly. (That thread guide in particular is tricky to replace, and so tricky to remove that I don't think I've ever seen anyone selling one as a spare part.) Rust isn't usually isolated, so I'm willing to bet that if you look at the machine's undersides, and behind the faceplate, you're going to find more rust. If you do, removing that from those internal parts requires major surgery, i.e. removing the needlebar, removing the main shaft, re-timing the machine, et cetera. This is not a problem if you're mechanically adept, or patient enough to learn, provided you've got the right set of tools (a comprehensive set of hollow-ground screwdriver bits in a variety of sizes will serve you well).
All of this doesn't mean this machine is unfixable--it just means you ought to know what you're getting into. If your priority is to fix this particular machine and learn something, I'd say dive in, as long as you've got the time and money. Rescuing a machine can bring a lot of satisfaction. But if your priority is to get to sewing in a timely manner, I think you'd be better off looking for another machine.