The body was made by Compagnie Facel-Metallon. FACEL which stand for (Forges et Ateliers de Construction d'Eure-et-Loir) was company created by Jean Daninos before he went on to produce cars with that name.
I was unable to find anything about any Simca Aronde Week End made by any coachbuilder other than Facel.
The puzzle car does have a few differences with other Week Ends, it has some kind of ornament on the bonnet, the handlebar moustache like trim is placed slightly lower than on other cars I've seen and the front bumper guards are low, all other cars seem to have high front and low rear guards, probably when the car was restored rear low bumper guards, were used at the front and a new grille was made.
Please unlock because I doubt I'll find anything more.