Now now chaps!!
Air Atlanta Europe and Air Atlanta Icelandic are both owned by Avion Group who in turn own a majority stake of Excel Airways.
'ACTUALLY' Air Atlanta Europe does fly B747 regularly for and on behalf of Excel Airways. Chances are if your on a 757 or 767 they are owned anyway at the moment by Air Atlanta Icelandic (Avion group)
I reckon you will be either on the 747 or 737, the 74' departs around noon, the other later on in the afternoon.
Enjoy....!