Wlad wins under modern rules. If they are fighting under Dempsey era rules, Dempsey wins. Those small gloves, and he's allowed to stand over a fallen opponent and thwack him as he's trying to get up...that's no place for Wlad.
Wlad would knock Dempsey down with every rangefinding jab. So by your logic, the very first jab lands sends Dempsey to his grave. Wlad KO1 under any rulesdeal:deal