Gulf Coast Lead Bars?

[novalty]

Has anyone had any experience with lead bars with casting impression "Gulf Coast" on them? My FIL just picked up some from metal recycler in central Maine of all locations. My guess is that they were used as ballast for a boat. He said they were 15"x3"x2", and that they were pretty hard as he used a hydraulic press to break them into more manageable sized peices.

Thanks in advance for any info.