At least one of you is on the right track. Unlike other aircraft of the same kind, its primary target was not to make long distance flights, though very long-range versions were developed afterwards.

Monocoupe Monosport G. The second picture shows NC11791:
http://www.shu-aero.com/AeroPhotos_Shu_Aero/Aircraft_M/Monocoupe/Monosport_G_01.html

Last clues after 3 days: it was manufactured by Caudron, and the designer is from Brazil.
I’ll give the answer tomorrow if there is no taker.
Adrien

It is not Italian either. It was designed by an engineer from a non-European country, and built in France by a large aircraft manufacturer who made several aircraft on demand for independent designers.

Let’s try this one, with two pictures showing the same aircraft in different conditions.

Adrien

Yes it is, a complete version of the picture with the flag on the fin can be found there:
http://www.tuncay-deniz.com/ENGLISH/V__HURKUS/v__hurkus.html
Your turn!
Adrien

Thanks Moze. Let’s try this one:

Adrien

Correct, this is the Cañete Pirata, made in Spain by Antonio Cañete Heredia, also called HACR for “Hidro Antonio Cañete de Reconocimiento”.
Your turn.
Adrien