Trivia time: The '57 Chrysler 300C, and the '57 Cadillac Eldorado Brougham (the one with the stainless steel roof....) are the only 1957 models I'm aware of that came with dual headlamps standard - and in 1957, they were still illegal in some states. I believe the 300C could be retro-fitted with the larger single headlamps, but I don't think the Cadillac could.
The 57 300, standard Chryslers, DeSotos and Imperials could be had with singles or duals, depending on what state the car was sold in. FWIW, I've never seen a '57 Merc Turnpike Cruiser with duals, only quads, and I've seen quite a few of them over the years. As for the other '57 Mercs, I've seen more with duals than quads. But 57 Mercs are kind of a mish-mash. Marshall - you're missing one other car that came with quad headlights standard - can you think of which one it is?
Was the Turnpike Cruiser a model introduced in the fall of ‘56. Something tells me it was closer to January of ‘57, which was around many of the newly built ‘57’s got quad lights.
Ooooooh you're good....most people don't remember that one. I think the '57 Nashes are pretty nice cars, especially the hardtops...