1934 Cubist collage oil on panel painting

A rare find.
Oil on panel and collage cubist painting.
Dated 1934.
Frame seems to be original to the painting.
Excellent condition.
On back of panel, there is another painting study signed G. LEFEBVRE (1887-1962).
But Georges Lefebvre was not cubist painter. Is this painting a trial he did ?
Or is this painting a re-use of wood panel, very common practice in the XXth century ?
Anyway, the painting is good quality. Collage is very interesting with linen, paper, canvas...
Composition is elegant and well balanced.

Dimensions :
With frame 37cm 30.5cm
Panel only 27cm 21.4cm