Customs '46 rear fender hole

Can anyone tell me what this squared hole in the lower right of photo is for on a '46 Super Deluxe coupe? I've seen it on other fenders but not all models. There is one on each side. See pic below.
Thanks, Mike

 

Possibly for the gravel shield that goes between the bumper and the body ?? Not sure if 46's had them or not.

 

I searched real quick like and that's what it is for. I'd say that the Super Deluxe was maybe the only version to have bumper gravel shields.

 

What he said.