Yes, the FDCPA would protect you. If the SOL for the judgment has expired, they are SOL, too.
Another thing to remember: When a judgment is involved, and you are living in a state other than the one it was filed in, they have to domesticate it in the state where you are living now, if it has not already been done.
And, the judgment has to still be "live" in the originating state to be able to domesticate it in another.
And, the new state's SOL for judgments must not have "run", too, for it to be filable and subsequently collectable.
Another set of complications--for them--which is often not taken care of properly.
Too expensive for a JDB to usually do so.