Hmmm, i'm wondering about that too.
I'm using "updated" 2D work for my DK Cab. But my goal is to stay along the lines of the same feel that all the old official cabs had. I think in this case the best course of action would be to look at a bunch of the art from the time period, and decide on a style that was popular, but one that still fits the classic feel of the cab itself. Going with something from the Cart's art isn't a bad idea. And its definitely a more serious game then say, Mario, or Popeye was. Much less whimsy.
I think the problem is that its such a serious game compared to the cartoonish ones all the other nintendo uprights were. Maybe to avoid showing characters in the art, and instead use symbols. Keys, hearts, arrows, hookshoots etc. If you can overcome that with the art then you'll have sold gold (excuse the pun).
let me think on this...