“are there any firms that specialize in representing Scouts in legal proceedings?”

It’s interesting that the early days of BSA was ran by James West—a lawyer.
But when you say firms representing Scouts--- there are many; probably one in every major town--- at least willing to represent scouts. So I’m not sure if I understand your question.
But what about firms representing BSA? It also appears, after a lot of reading, they have also been represented by any number of law firms around the US.
-Barry