I really like the growling sound of the reeds on this song and I'm wondering if the box is tuned a specific way, or just plain tuned, unlike my box that is old and hasn't been tuned in a while.

You can ask Wilson, he knows it.
Maybe he had done something with the stops.
His email is somewhere on the forum, you can easily search for it.

It seems like a standard Cajun tuned D box to me. I think that is Marc's famous "red box" that many say sounds so good, I think maybe the same one Marc is playing in the move "Southern Comfor" (??). Some just plain sound good. Never heard for sure what reeds it has, maybe someone here knows.