If they are on paper, all the flight coupons in your folder will have the same long number at the bottom (except for the end digit which indicates the flight coupon number).

If American Airlines made your booking, I'm sure you will be just fine - airlines wouldn't usually book flights outside MCT). The minimum connection time does not allow for late inbound aircraft (which would not be your fault anyway) so I am sure both American Airlines and British Airways would interline your baggage.

Enjoy your Holiday!!!