NOTE: None of this was my work, but I salute their efforts.
The top-loading NES2 always had cruddy video, there are faint vertical lines across the screen. Even worse it only outputs RF, but these three links will lead you to happiness:
GameSX -Kevin Horton's AV mod
Darthcloud -Leonk's new circuit (FC2 not needed)
NesDev -Wayback archive of initial discussion