"Schpountz" is Slavonic slang for a simple person.
The movie was shot a second time because the confusion around the first shooting when Marcel Pagnol was writing the scenario day by day. Unavailable for the second shooting, Pierre Brasseur was replaced by Roger Forster (I) but some of the shots involving Brasseur were still used.
The song Fernand Charpin sings is called Magali (Ò Magali, ma tant amada, mete ta tèsta au fenestron // O Magali, my dearest love, lean your head out the window). It's in the Provençal dialect of Occitan and was written and composed by Frédéric Mistral.