You should just go talk to an actual Air Force recruiter with your DD-214 and see what they say.

Be prepared for a no. I will tell you like I tell most kids I talk to in the community that its almost impossible to get ahold of an Air Force recruiter. They are in no way hurting on numbers, so they can be very selective. They tend to treat new recruits like simple numbers, so I would probably assume that a RE-3 waiver would get the exact same treatment, if not worse. If you are really wanting to go back in, I'd go with the Army. You'd have your best chance with them.

RE-3 codes need waivers. Air Force aren't really known for wanting to take prior service that need waivers. They hardly take prior service with RE-1s. Keep shopping around to other Air Force recruiters.....but be prepared to get answers that you are not going to like.