Have you tried phoning BA? You ought to be able to get BA to put your BAEC number into BA's PNR, and BA may then be able to give you the locator/reference for that. You may find that the booking will then show up in your BAEC welcome page list of bookings too (although it's possible that not all of the flights will show, as this is effectively BA's copy of the main PNR, with only the bits that BA needs to know).

You should be able to claim Avios and TPs for DUB-LHR. It matters not who booked the flight; what matters is that you are flying it. The only possible fly in the ointment is if the fare is somehow one that doesn't qualify for earning, which would I think be very unusual.