If I were you I would wait for my rating to see what your effective date will be. Then I would take what Berta has posted and use this as the basis for an earlier effective date. If I did not get the earliest date I would take my case to a VA lawyer. I say this because I think the VA will fight giving you the earlier date and it will get complicated legal questions will arise. The main thing now is to get the highest rating possible for the PTSD. Then go back and attack your effective date if the VA does not grant it back to 1996. The evidence to grant PTSD was in existence in 1996, but the VA did not have it, so they say. Since this involves a lot of retro and gets into legal questions I think this is the kind of claim that is made for a lawyer to do since I bet you will be in appeals for a while. Better to sit down with a paid legal expert and get the pros and cons of this case ironed out before you launch a hunt for EED that could take years. I think Berta has nailed the issues, but you need help taking it forward. If I were in your shoes that is what I would do.