Cargo hooks on my '62 bed question

[C-10cutty]

I've cargo hooks on either side of my truck bed, on the outside. Black and held in place with square nuts. Were these a dealer option back in the day or did the PO buy them and put them on? The holes and spacing look to be done with precision, no shade tree mechanic look. I sometiimes see the same hooks on other C trucks. I don't think they look bad and was considering re-painting the hooks and put them back on when the bed is done.

Just curious and any info appreciated.