I traveled to St. Louis a few weeks ago on an AA MD-80 from LAX. I normally log tail numbers of the aircraft that I travel on. However, this was one of those trips where they very cleverly park the aircraft so that neither the registration or the fleet number is visible before boarding. By the time we got to St. Louis, it was dark, and again, I was unable to see a reg or fleet no. I did see a placard on the instrument panel as we were disembarking that appeared to be "4XX". (That is the number four followed by two X's.) I think this might be the fleet number assigned to this aircraft. Furthermore, some very subtle details in the cabin indicated that this was an ex-TWA aircraft. Can anyone here tell me the registration of this aircraft, or where there is a listing of AA's fleet numbers?
(On a subsequent trip, I ran into the same situation, but was able to ask the captain, who was lounging in the cockpit doorway during boarding, for the reg.)

Thanks for any help.
Bob