Wow - prompt and concise answers, full of helpfull information. Many Thanks.
Flights are back from AMM (Jordan) (RJ) and then to LCY on BA. I have allowed several hours between arrival and departure, and if I get stuck in Berlin because of a late AMM-TXL it's not the end of the world.
Flying Crown Class on RJ, so will see if they can be persuaded to interline the bags to BA. I suspect not, as separate PNR, but can but ask. Will be my first trip on RJ.