Thanks to all for your nice comments. That´s true Jim, the different shades noticed for you in the pic are a mixed of Duro with Milliput (fifty/fifty).
This mixed is used in a thin foil and it is ideal to make ribbons, hat wings, overcoat flaps, etc.
Cómo le vá Charlyq, the idea was taken to the book "La defensa del Rio de La Plata" of José Mª Bueno Carrera, a famous and prestigious spanish & colonials uniforms expert with several books publicated. In the top of this topic can see the
picture while i based my work.
Saludos.
Miguel