B-L-C spotlight and Bumper guards

I am going to be listing an absolute pristine spotlight that appears to be from the '40's. It's 6V and under the bottom it say, "B-L-C"

I've sold NOS '57 Chev B'guards that were stamped "B-L-C" but can find nothing about who they were and their affiliation with GM or other car companies.

Any help there about them or this light? It was on a '48 Chev Fleetline

 

I'm very interested in this question. I have wondered the same thing. I've heard that they were an aftermarket car part company that sold their products in the auto parts stores of the day. Obviously, they made good stuff because it's still around. Somebody surely knows more.

 

I just saw a pair of GUIDE head lights for a '30's Chev and they were also stamped BLC along with the Guide name