True for the taillights for sure - not sure I've seen a '64 Dart wagon with backup lights.
My '64 coupe has the backup lights in the trunk lid - my '64 wagon doesn't have backup lights.
Maybe get some and put them in the valance under the bumper?
63/64 wagons had round housings that mounted just above the bumper on the flat part of the sheetmetal below the taillights.
I will be using the 63/64 backup lights instead of the OEM backup lights in the outer taillightsIn my wagon. The OEM B/U lights will be used as separate amber/yellow turn signals.