This whole thing w/ pre-ban lowers, if it was not a whole rifle before the ban and the lower was bought after the ban, then it's a post-ban, correct?
What if the lower was bought as a parts kit originaly, and the lower was then sold after the ban, is it still considered a pre-ban, so I can build it in pre-ban form legally????

If the lower was combined with sufficient parts to assemble a weapon configured as an assault weapon under 18 USC 921 on a date prior to 9/13/94, it is considered preban receiver under 18 USC 922(v)(2) even if the "kit" wasn't assembled into a complete rifle and the lower is sold later.