For this car, I know just the builder and the year.
expert
pros
French ?
Yes, that's french
Delage?
Farman?
not Delage, not Farman
Panhard Levassor ?
not Panhard
Peugeot
Georges Irat?
yes Hiawatha, Georges Irat is correct. Now, I locked for you for find the year.
Grand Prix de Provence, 1926
1926 is correct, GP de Provence, I don't know
It is Maurice Rost at the 1926 GP de Provence as Hiawatha correctly says. It won its class and finished 6th overall.
The car was fitted with a 3-litre engine but production of those engines did not begin until 1928, so maybe they used the race for testing the new motor. I am curious about the headlight. The race was held at the Miramas banked oval, so it is possible that the car was used after the race to attempt endurance records (running at night) or maybe it was driven down from the factory in the Seine departement.