For today's attempt I'll try H-6-e, where I think the link is the name Surirey.
If you google "Peugeot 403 ambulance", which is what H looks to be, the name crops up as a coachbuilder in Flers, Normandy. It seems that they did some car bodies, but were more concerned with station wagons and commercial vehicles, and made something of a speciality of ambulance conversions.
Googling the name on its own soon brings up Extra e, a paratrooper called Michel Surirey, standing on a Simca Ariane, which is itself balancing on two wheels, being driven by a stuntman called Jean Sunny, who is described as "world champion of motor acrobatics". Photo taken in the Bois de Boulogne, Paris in 1959.
It also brings up Architecture 6, which leads to the website of a company called Surirey Jagou. As this was founded in 1939, and has the same address as the ambulance converter, I'd guess it's the same firm, though now a specialist metalworking company rather than a coachbuilder. 6 is part of their offices at 18 Rue du Parc, Flers.