Tail light lens

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.

9DC6EF21-4E11-4253-92C0-7D05C4343314.jpeg

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.