My COE had Arrow armoured clearance lights from the 1950s. The company still exists and I was able to order new lights that were essentially identical, only 12 volt. I have not installed them yet but all I will have to do is change the bulb to 6 volt.
Looking through their catalogue they have similar lights to yours but without the metal strip across the lens.
Try this link and scroll through the pages to see the different lights.
You will have to call them to order. They provide products for truck and bus manufacturers, not the usual consumer but they will talk you through an order.
http://www.arrowsafetydevice.com/marker-clearance?p=1
