Deltican

Would someone mind helping a domestic flying fanatic out? This may need to be moved to the BA forum, not sure.

Flying at the end of June from DFW-LHR on AA.. have a long layover at LHR and then catch a BA flight from LHR to IST to meet up with family and every time I have ever been international it was a non-stop from ATL so this is all very new to me. The questions I have are..

When I get to LHR, do I have to claim baggage / customs / etc. and then recheck on BA for the leg to IST?

As an EXP.. I thought I could get my seat assignments on BA? However iten still shows unassigned.

Any suggestions would be appreciated..

Thanks