Not a regular BA flyer, so please bear with me. Flying later this week ORD-LHR in CW, connecting to Icelandair (FI) to KEF. (Not sure if this is relevant, but connecting flight is on a separate ticket booked directly with FI.) Layover at LHR is 6 hours. BA phone agent says BA has no interline agreement with FI, so we have to claim luggage and take it from T-5 to T-1 to recheck it. Two questions: (i) to any of you who have connected BA-FI, is this right?, and (ii) if we have to claim our baggage, will we be on the correct side of security to be able to use the BA Arrivals lounge or any other Galleries lounge in T-5 during our long layover? Thanks for any advice.