I'm pretty sure they were not a factory item, no mention of them on the Heritage accessory page, no wiring in the shop manual diagram. My '57 2 ton LCF has no cab roof lights, I did add all DOT spec'd grain box lights as well as lighted west coast mirrors.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy