Michigan and Pennsylvania stay Dem
Florida leans Dem/ tossup
Ohio tossup
Iowa leans GOP/ tossup
Wisconsin probably GOP
New Hampshire in play
Nevada, Colorado and Virginia really in play, with some doubts over his possibilities to overcome the Dem structural advantage there, but definitely doing better than Trump.
I have to disagree with your analysis. Romney would under-perform against Trump's margins with working-class voters. Think of places like Parma, Ohio which was a Obama-Trump city. There's nothing to suggest Romney world perform any better in these types of places than he did in 2012. Further, Romney would be damaged by being a re-run and all his baggage would weigh him down, cancelling out whatever gains he would make in the suburbs compared to Trump. (Not that I really believe the suburban trend towards Democrats is entirely Trump's doing).
