3bet or fold pre for me (always a fold without any reads against full stacks who may be regs.) If he's given me any reason to think he's loose, like if he's running 50/40 over them 20 hands or has a silly stack size then i'm 3betting for value. If he is a reg and is folding to enough 3bets i will use AJo as a 3bet bluffing
hand as calling AJo doesn't do very well against tight ranges, and calling just sucks because without being suited especially, the loss of initiative really hurts, you could maybe make a case for flatting it pre if you wanted to let a big drooler in the pot who might not call a 3bet or i suppose if you had some sexy read that villain fires 90% cbets and is completely honest on turns so we could float him. But yeah without reads you probably should just fold. I like the way you played it post flop though.