I finally stumbled across some new photos of the 1937 REO fuel tanker

found on http://www.cardesign.ru/forum/diskussii/obschenie/1352

the only other image I ever came across was in 2009: http://justacarguy.blogspot.com/2009/02/there-may-never-be-day-in-future-when.html and since all 3 images show the REO with the same side marking advertising Super Plume Ethyl, I suppose it's the only one vehicle in these 3 photos