It would probably be most accurate to designate the aftermarket taillights as replacements for that chibbie application instead of simply chibbie parts. They were likely made in a foreign country and had no direct link to GM. The comparison to the connecting rods is accurate as well. I have used rods in several FE engines that had some dimensions in common with the BBC articles, but none of them were GM-sourced and in all cases, had some aspects that had nothing to do with the BBC.
KS