I might draw some fire for saying this again, but oh well: If that kind of thing is going on, RTW might just be what your area needs. Although I'm opposed to it, that might be enough to get your local's act together and stand for everyone, equally, instead of just the people who pay the most in dues. If people don't feel like the union is protecting them, they'll stop giving the union money given the chance. I think it would be wiser for the local to earn younger members' respect early on, not when they're fighting for their life. But they're in control of that, not me.
But if you can prove that your local gave someone who's been there longer better representation than a newer member (in a similar situation), I'd file NLRB charges in a heartbeat.