It can be done; SAG can complete an agreement. Done jointly with AFTRA, the new agreement seems to encompass web, cable, and broadcast issues, as well as Hispanic spots. "We have achieved a deal that brings significant improvements to these contracts," said SAG chief negotiator John. McGuire in a statement. 'Our gains include establishing the first-ever payment structure for made-for-the Internet and new media commercials and significant increases in wages during a very troubled global economy.'" Nicely done.
So now let's get a deal done with AMPTP. The truth is you have no leverage and you aren't going to strike. It is in no one's best interest. You've proved you can work jointly with AFTRA; perhaps, it is best to use their signed agreement to complete yours.