They were made long enough that there are several eras, and a lot to cover. In short, pre '64 are the best, and '64 until late '70s are the worst. You can recognize these by the cartridge lifter. The pre '64 is machined, the '64 till late '70s are stamped. There are other differences as well, but it is a big topic. I have one AE and like it, but some are dismissive of them. They are from the early '80s onward.
