The Magpies allowed Toney to slip through their fingers two years ago and Steve Bruce's side are struggling to stay in the top flight with just 18 goals from 16 Prem games this season.
Yet Toney, 24, has already bagged 16 Championship strikes alone for Thomas Frank's high-flying Brentford, which meet Tottenham in the Carabao Cup semifinals tonight.
Fry, who has unearthed many diamonds at the club, signed Toney for Posh and insisted: "Ivan is the best striker we've ever had.
"He's better than Britt Assombalonga, Dwight Gayle, Conor Washington and Craig Mackail-Smith.
"Why? Because of his defensive qualities. None of them went back and headed the ball away at corners and free-kicks like he did. He got 49 goals for us in 94 games and was our best defender last year!"