[Sirrotica]

On a rusty surface body panel such as the bottom of a door, I wire brush the loose rust off, then coat the bare metal with phosphoric acid (phosphoric acid can be bought at big box, HD, Lowes, stores for cleaning concrete floors). The acid neutralizes the rust, and can be primed over after it dries. Primer is an important step when working with surface rusted metal.

I don't claim to be a body man or painter, but I've used this prep after reading up on it. It worked well for a car with failed lacquer paint, and surface rust spots where the paint failed.

If there are actual rust through holes, then you'll have to handle that in a different way.

On the fuel filter, you can try the glass bowl type, but there are 2 drawbacks with them. The gasket between the base and the bowl have a tendency to leak, and you have a glass bowl that is susceptible to cracking, or breaking due to a freak accident. If you're just looking for a functional filter I would go with a traditional inline metal canister, but you may wish to be more period correct with the glass bowl type.