School me on '61 409s and L89 Novas, please!

[442w30]

This is a two-part question, although unrelated:

1) All 1961 409 cars I've seen have been Impalas (presumably SSs). I know the SS was a package that can easily be faked. But the 409 was available in other lines, so it's possible to have a Bel Air 2-door sedan with the 409, right? Is there any way to tell its pedigree from the body or it requires paperwork as well?

2) This weekend, I saw the black 1970 L89 Nova at the Greenwich Concours d'Elegance. I know there's been some controversy regarding this car, so can someone make an objective attempt to tell me what the deal is? Is it an issue of the owner using deductive reasoning to arrive at a conclusion that it's an L89 car, while there is no paperwork to prove it, not to mention that the fact that it's a 1970 (versus 1969) car makes it all the less likely that it's an L89 car? I'd like to hear an attempt at impartiality regarding this car . . . and my apologies if it may appear like a rehash from a previous thread.

Thanks, Chevy folks!