Looks like no prop spinner.
This discussion highlights just how much airplanes had evolved between 1927 and 1937. The Lockheed Electra was modern enough to have a service life into recent times (are any still in regular service?) which would be unlikely for most 1927 airplanes (although there were some Ford Trimotors in service at least as recently as the 1980s). And the White Bird was a bit old-fashioned even for 1927. Most of the contenders for the Orteig Prize were high-wing cabin monoplanes. My first though on seeing the profile drawing of the White Bird was that it looks like an enormous SPAD, the airplane in which its crew had made their reputations. I wonder if the resemblance was intentional. That aside, it was weird with a weirdness unique to French engineering. I write this with fond memories of a Peugeot that was a joy to drive and a nightmare to work on. Fly an open-cockpit biplane from Paris to New York? Trust to an untested landing system, with no good options if you couldn't find smooth water?
Their preference for an open cockpit -- common to other pilots at the time -- is similar to the attitude of "serious" drivers at the time that open cars were always referable to closed cars, and never put the top up (one can find this referenced in the Peter Wimsey novels -- Dorothy Sayers always got her cars right). Even some early airliners had a closed cabin for the passengers and the pilot freezing in an open cockpit. Also reminiscent of the formal cars that had an enclosed rear set and open driver's seat.
Regarding the broken part that started this thread, my questions are, how thick is the metal (is this a casting, stamping or what), and what parts of the airplane are known to have been painted that color. It seems to me that the only parts that could be painted outside and have oil on the inside are the crankcase, and the external oil tank, maybe some other parts of the oil feed system.
An explosion might have occurred from impact on a crash landing, but seems unlikely in flight. However, the nearly empty fuel tanks are a greater explosion hazard than full tanks, due to the air and fumes inside. What burns is the vapor, not the liquid.
LTM,
Don