I'm gonna guess Dwight Twilley.
Without looking I'd have to agree. That's a huge Katrina in 1975.
Your instincts are not wrong, guys. Twilley ignites in a few more songs.
Meanwhile, BOS to Blackmail, about the only 10cc song Dave ever plays in 75, even though I'm Not In Love was the bigger hit.
ETA: Just checked: my instincts are right on that one. Nine appearances in the DB for Blackmail, but only three for I'm Not In Love.