Morning Karark
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Good call on the Puffer; I'd never have found that one in a million years and Aerofiles wouldn't have helped one bit!!
The reason I put the smiley in my post and question mark after the name, was when I flipped the image I could see it said
Huff-Daland Duster on the fuselage and D-49 on the tail, (you can see it here): Keystone : Puffer | Flickr - Photo Sharing! I thought it was either an early Christmas present, or was too good to be true (and it was 
)
It seems like the Puffer was a bit of a "paper aeroplane" and Keystones part in it was a rather thin re-paint and re-name job!
From Canadian Wings:a contract was placed with Keystone Aircraft Corporation of Bristol Pennsylvania for two Huff-Duland aircraft which had specifically been designed for crop-dusting. One of the aircraft was to be equipped with standard wheel undercarriage while the other was to be delivered as a float-plane. The Huff-Duland aircraft were then re-designated as Keystone Puffers.
No quibbles though, A good challenge from Brian and a good bit of sleuthing from you
Now then; I'm pretty sure I saw that "looping the loop" shot too while I was searching, could it be from the Sablatnig SP's or the Gotha WD's ?? There were others as well as the Friedrichshafen FF's that had the correct look, but IIRC, those two had the wing shape too.
I'm out all day now, but I'm sure if anyone else is out there, they can home in it after your reply to elimate them or narrow it down. Have a good day