Did some searching and I think that my upcoming situation is doable, just want to get the experts opinions. Next Jan, we are going SEA-JFK(AA)-JFK-LHR(BA)LHR-AUH-MEL(EY). The question is, these are all separate tickets and we have connection times in JFK and LHR of 2-3 hrs. I would obviously like to check luggage all the way through and I know there is an interline agreement between all these airlines. My main concern is LHR where we have to change terminals and have the shortest connection time, 2:20. If I have all of my itineraries printed off, will the AA agent in SEA have the ability to do this for us. Thank you!

Recently I tried to do this for a Virgin America to Cathay flight and Virgin would have non of it.