I recently flew on a 737-400 with AS. Its reg is N754AS. I noticed that all the seats had headphone ports on them. I've been flying with Alaska since the late 80's and have never known them to have IFE. I checked with airfleets.net and it shows that AS is the original operator of that plane but the Boeing customer code is Q8, which is not Alaska's code.
So, does anybody know where this plane came from that it has audio systems in the seats?