I'm active duty AF, my OCS class date is in Oct. You will not have to sign your paper work until the day after you separate, you are an exception because you are still AD. When you fill out your separation paper work with the AF make sure you separate at least two weeks prior to your OCS class date, the Navy apparently needs a couple of days to cut your OCS orders and they can't do that while your in the AF.
Your recruiter should know this....you may want to ask him to remind the board members that this is why you have not signed your paper work yet. My recruiter received a call from the board telling him they were going to take away my pilot slot because I had not enlisted yet. He explained the situation and they said no problem.
Also,in case you didn't know you are allowed to take terminal leave, I am taking 55 days of leave before I go to OCS. I did not know I could do this, otherwise I would have used all my leave. I have 80 days, I will have to sell the remaining balance. If you know of anyway to transfer it please let me know. I buddy of mine transferred AF to Navy and lost all his leave but after huge hassle he was able to get most of it back.
Please let me know if you have any other questions,
Mike