Peterson's not going to bring you anything. I wouldn't even want him unless the alternative is I'm starting somebody's third string running back. He's still got talent to help an NFL team, but he's probably not going to be good enough fantasywise to start on anybody's team who is set to make the playoffs. Then again, that's what I think about him. You might be able to find somebody who likes him.
Henry is interesting though.
If you find a guy who is weak at running back and strong everywhere else, you might be able to get a second round pick next year for him. I'd say at worst a third. I doubt anybody would give up a first rounder, but you could try. Sometimes people don't think clearly about next year when trying to win this year.
Mine
https://forums.footballguys.com/forum/topic/781739-trade-for-cooper-whir/