@CalBear---you never heard of either Hardees or Burger Chef, correct? But what about Carl Jr?
I do not know at what point Hardees merged with Carl Jr. When I was a kid in the early half of the 1970s, I could compare them because we had Hardees in Panama City, Florida, and Carl Jr. all over southern California. If it were not for having seen one commercial once for Burger Chef, I would be quite mystified by all this talk straight out of a parallel universe to me. But in fact once, and I cannot pin down just where or when, I did see a Burger Chef commercial. It could have been in Los Angeles, where presumably the chain was making an aggressive attempt to penetrate the local market; if so this would have been around 1974-75. I really don't think it would have been in Montgomery, AL because I suppose that was surely Hardees territory; I suppose my next chance to see it would have been when I lived at Langley AFB in the Virginia tidewater, Hampton/Newport News media market. Could BC have been trying to get a foothold there? It seems unlikely to me.
So, somewhere or other I briefly lived where Burger Chef either was on the decline and on the way out, or trying to insinuate its way it. Either way I never happened to drop in and try it. The Los Angeles theory seems strongest to me.
Meanwhile, as far as I could tell from the grassroots and vantage point of a child, Hardees and Carl Jr were quite different, yet shared a lot of similarities, presumably because they were pursuing a similar niche. I'd have to look it up to see just when one acquired control over the other; they persist as separate chains attempting to monopolize different markets. I believe nowadays their product line as largely been "streamlined" into one standard probably with small regional variations.
The combined chain has intruded into political polemics recently, and indeed while I did not notice any political slant of the Hardees chain, Carl Jr. took a hostile stand against gay liberation in the early 1980s--a fact brought to my attention in the summer of 1982 by a Knights of Columbus spokesman who urged his audience to therefore support the chain against those he characterized as the "homosex community" who were boycotting.