The story of the car as published on a well-known classic car blog last year, when the car was auctioned for a cool quarter million euros at Le Mans:
"This car began life as a 135 Competition model that competed in the Monte Carlo Rally when new. In 1949, the car was re-bodied by Antem with the long, sporty coupe you see here [...]. In 1979, the body was removed from the 135 chassis and sold. In 1988, the body found its way onto a Delahaye 148 L chassis (that was originally fitted with a Letourneur et Marchand Sedan body).
The engine is original to the chassis and is the type from a 135 M: a 3.5-liter straight-six making 115 horsepower (with three carburetors)."