All flights to Bahrain are now with the 21st Century cabin - this has been announced in local rag.
However, I don't think you were on ZD - both it and ZE are now with a new operator:
MSN L/N A/C MODEL ENG. MODEL DEL. DATE LAST KNOWN OPERATOR REG. NO. F/N SELCAL PREV. REG. [COMMENTS]
27108 17 B777-236 GE90-76B 1995-12-28 KHALIFA AIRWAYS (BCCI) 7T- GJ-DR G-ZZZD, N702BA [OO]
27109 19 B777-236 GE90-76B 1996-01-12 KHALIFA AIRWAYS (BCCI) 7T- GJ-DS G-ZZZE, N703BA [OO]
27105 6 B777-236 GE90-76B 1996-05-20 BRITISH AIRWAYS G-ZZZA GJ-BS N77779
27106 10 B777-236 GE90-76B 1997-03-28 BRITISH AIRWAYS G-ZZZB GJ-CR N77771
27107 15 B777-236 GE90-76B 1995-11-11 BRITISH AIRWAYS G-ZZZC GJ-CS N5014K
As for standing room only, as of March 30 BA will introduce 747-400s on the 124/125. These will be in the high yield config with the same number of premium seats as the 777 but more economy (and world traveller plus).