Thanks for clarifying, much appreciated and I wasn't taking it as an argument.
The sale of tooling with the lowers as a kit became an issue last year when the rules went into effect.
Even then though, the existence of 80 lowers in and of themselves is not being challenged . It's the serialization aspect. As of last year, if you are a licensed dealer, with intent to sell, you are required to serialize them. Private owners, NOT selling are good to go. In fact, you can still sell if you're careful and can show no intent to be a manufacturer. I would simply avoid selling them altogether though. That has always been sticky.
There is nothing in the rules that went into effect last year that prohibits them.
However, all that said and done, we all make choices. I do agree polymer lowers are a joke and I'd go further and NOT buy a billet one. Forged, while not as tacticool looking, are about twice as strong. If someone has ever used an M-16 to break a fall/dive to the ground, they'll understand.
Thanks again