As I understand it
there's more to it than just the lifting of the ban...There are other BATFE rules in place, such that if you modify it so that it is not legally importable, under some of these other laws, its illegal. Check the BATFE website, and if necessary write them with specific questions...This is very complicated, and its hard to get straight answers, on exactly what's legal...You don't wanna get in a bind with the .gov, its just not worth it...
Additionally, as mentioned, state laws may differ...Here in NY we have and exact restriction of the federal ban, and it didn't expire, so we still have all the same restriction...
Not a lawyer, but I've checked this out for personal reasons (and come to the conclusion that there's not much I can do, legally)...