This worked out well for me, am going to be in DXB on 10-Dec and so booked a DXB-LHR-DFW-AUS on 13-Dec with the long hauls both on 744s (sucker for the nose 1A seat on the 747-400s

)
I booked directly on BA, it ticketed instantly and when I checked this morning it still shows FIRST confirmed on the BA site.