I dug in my notes and found a quote from Sound of Wings, no page number. A Wire dated Feb 13 , 1937 ,Putnam to De Sibour , London , " Fuel consumption normal cruising speed per hour by weight 310 lb." 310/6=51.6 GPH These notes are yellow so from way back. Context justifying heavy fuel loads over British Territory. Max cruse for the engines would be 64 gph so it is not simply a claim for all it could burn.
Still looking for Darwin news papers.
Neff