Just want to give a big thanks to everyone for their replies, especially to Friedrich and Buckram for uploading those documents! This is my first post on the ED forums and it was heartwarming to get such a positive response so quickly.
AP 129 remains elusive unfortunately, and from what I can gather this was this big resource text on everything from basic airmanship to combat doctrine. There are digital copies being sold on ebay, but I was hoping someone would be able to share it for free. If I do end up with it, I'll be sure to share it with you guys!
Cheers