I saved these pictures from BAnQ (Bibliothèque et Archives nationales du Québec) many years ago and to follow the rules of the Hamb at the time, I didn't save much "stranger" cars pictures.
Hard to find an image of a real one. I did find some information in one of my Chevrolet books. In 1955 Chevrolet came out with 3 different Forward Control Chassis options that independent builders used to build these vans. Along with the chassis Chevrolet produced the grille and headlight units as standard equipment. In 1960 one of the independent builders, Airvan continue using the Chevrolet chassis and replaced the Chevrolet insignia with their own.
Around that same time frame 1850 Holleys were advertised at $26 and the manufacturer and seller still made a profit on them.
I’ve been wondering the same thing. Just a guess but some of the images seem to have a local ordinance violation, could city inspectors have been issuing citations and they were documented with photos?
These guys worked for the city of Montréal at the expropriation department. These building are gone since the mid-sixties. That's why the photographer didn't focus at the cars, but to the buildings.