When I purchased my '48 Chevy 1/2 ton, there were some "mystery" holes in this area. My carpenter brother John took this vintage extinguisher out on a demolition job that he was on. He gave me the fire extinguisher. On a whim, I wondered if it would fit in this location. The bracket holes fit exactly--dumb luck!!! Since my truck originally was a road department service truck, I decided to mount it there. The contents of the fire extinguisher were discharged, and I cleaned up the canister and the bracket. It has become a conversation piece.