I am sure none of those are vignettes from the lens. It's an intentional lighting and filter effect. It looks great, very atmospheric and painterly. I hope it's not taken away, it would diminish the terrific deliberate composition and lighting of Kersh and Suschitzski's and make everything look boring and flat. It's hard to get vignettes on longer lenses like those anyway, unless they were on a zoom, which they likely weren't, as Kersh shot pretty much all on primes. The "vignetting effect"-look is a deliberate stylization in my opinion, not an error to be erased, it's part of the look of the film.