Headlight I.D.???

I just got these for my 34 Ford. Can someone help me I.D. them? The marker light is round and there is a small hole just behind it where a cover of some sort might have been viveted on. The tag is just behind the hole and has been painted over. I hate to mess with the paint so am looking for the easier way - the H.A.M.B.

 

They are BLC's. I forget the numbers on the tag.
Clark

 

They are BLC 904 A

 

What does BLC stand for and what vehicle were they made for?

 

Bright Light Co, maybe spelled different not sure...

Mostly a replacement for older trucks when sealed beams came out. Trucks are the best place to look for them in yards.

 

Looks like a 6014 sealed beam.