Gentlemen--Fortunately for us, 1936-1937 was a different era. The things we learned about lead in paint primers probably were'nt known in 1936 when the Electra was being built. But--just because this piece of aluminum has 'red primer', or 'red paint' doesnt mean it was off a WWII aircraft, or the Electra. Because, we dont know, because we havent found out whats on the reef yet.
All of this discussion of what it is or isnt is right now speculation (if I can use that word Marty). We know of the missing 'friendly' aircraft in the area ---see 'aricraft lost in the vicinity of Nikumaroro'. But, I havent found items relating to possible Japanese aircraft. They had large 'flying boats', the Kawanishi H8K, smaller seaplanes in Bougainville, the 'Rufe's", and even A6M2-N's Zeros with floats. So as much as I want to see the wreckage on the reef as being the Electra, until the expedition finds whats there, we dont know for sure, and other possiblities need to be mentioned. Including the B17. Granted, I think the possibliltes are extremely small, but even as small as they are, they are still there.
Back to the 'red primer/paint'---The piece of aluminum appeared to be a trim strip for a wing leading edge, altough it wasnt bent in the contour of that edge. Doesnt mean it wasnt 'altered' in the village. But---kind of looks faded like red paint might have been. As does have countersunk rivits like a external airfoil surface probably would have. Might have been from repair done from the Luke Field incident.
Tom