Not that I disagree with anyone else, but I figure if you added a set of lights from a model year 54-57, it would be in line with your theme. If it was a hit on this supposed motorama truck, there's no reason GM wouldn't or couldn't use them later on a production vehicle.
I think the big picture is that if you pick something that looks right and isn't instantly recognizable (like caddy lights or something) you're going to end up with that look you're going for. We as a community following this build may know, but joe-blow-at-the-car-show won't. I know that your theme is something that I as an "automotive journalist" (I use the term loosely) would definitely be very interested in. It has that "bigger picture" look and theme.
Not in line with what you're doing, but last year at SEMA the runaway hit was this car called the Mach40. It was a 1969 Mustang turned chassis-wise into a Ford GT40. It had that "bigger picture" look and theme. Everyone and their brother could tell.