"RJ": No worries. It's not something I intend to do, just a question born of curiousity. That's why I'm more than happy to accept your take on it at the moment and to be honest, I'm not sure I could read that enough to make it clear to me. I get that it's ok to switch back and forth without issue as long as you are not creating an NFA item along the way. Where it gets a bit fuzzy for me is HOW you are allowed to do it. They talk about kits by manufacturers and what-not, which makes it sound to me you have to buy an all inclusive kit in order to do it. Blah blah blah.
Probably just me being stubbornly thick headed, but I can say this much. Most people have never had BATF agents standing in front of them ruling on something (not-even-remotely) firearm related, and finding out first hand just how broad a stroke they can paint with. With all the docs and threats of legal action/incarceration that went along with it. Luckily, it wasn't my specific arse that would have been in the sling. I think.