Well, with no West participation at the SCAB union, looks like the only course of action will be to abide by the MOU, get single carrier status, have the APA be the bargaining rep, then enter into a MB SLI in which all "interested parties" are provide a voice to be heard.
My guess is the APA structures it so the east and West have separate reps, kinda like the TWA pilots got in the STL base closure grievance arbitration.
So, pretty much will be the Nic. once in front of an arbitration panel, and the parties to the Nic are there in front of the panel, and the SCABs have exactly ZERO reason why a never vacated, company accepted seniority list should now be rewritten to allow the to continue to SCAB jobs.