I think you have to add Rouen to your French vintage children's furniture pilgrimage next summer. The kid's design store l'Atelier Charivari has a seemingly endless supply of awesome, 50's-era school chairs, desks, and tables, but so far, I've only seen one of these on their blog. It sold in Octobre for just EUR68.
Turns out Little Fashion Gallery had one, too, that points the other way. It was from vintage dealer Bianca & Family, and it sold for EUR140. [It's gone from LFG's site, but the image and info are still on decofinder.com.] So they're rare, but at least there are two of them.
Also, grey bed in the background: Chaise enfant vintage [atelier charivari]
