What changes are needed for a piston-prop aircraft to withstand saltwater environment? I'm interested in WW2-era piston-prop aircraft. I want to know what changes are needed to make the aircraft withstand saltwater corrosion. Presumably these are different and more expensive than the normal land versions of aircraft, or they would make them that way in the first place.

I'm not interested in the usual carrier modifications, like tailhooks and wing-folding. For this question, I'm only interested in withstanding saltwater corrosion.

I have heard that aluminum resists saltwater corrosion very well. Not so sure about steel or wood. Are there differences in the air intake? What about certain delicate instruments like a pitot-static tube?

Edit: I was envisioning any combat aircraft that fight over the ocean, but especially the more exposed stuff like low-level torpedo bombers and seaplanes since they land directly on the water. Carrier aircraft is fine too.
There is no way to fully protect an aircraft from the effects of salt water corrosion, even when any aluminium is treated with protection products like Alodyne. In fact, there is no way to prevent corrosion from happening anywhere unless you protect the item in question. Corrosion can affect an aircraft even in the dry climates.

Even if it is not landing or taking off in salt water, just being close to a body of salt water will cause corrosion. All you can do is be very proactive in washing the aircraft with clean water after every day, and using products like Corrosion-X to coat surfaces with a corrosion protection film. Even WD-40 will do a great job of this, because it is not a lubricant, it is designed as a hydrophobic [W]ater [D]isplacement product. You need to protect both exterior and interior areas, even inside the wings. Just ask any mech who has worked on aircraft for any length of time at a location near salt water.

Tailhooks and wing folding do nothing about corrosion, it just helps get the aircraft on the carrier and allows for efficient use of the deck areas.