Dunno. All time p4p the highest HW I have is Ali at #10. The highest fighter that fought at LHW is Langford, #1, but the highest I have a fighter who is known mainly for his work at 175 is Charles, who I have at #5.
For their era, I remember seeing Tyson at the top of P4P lists and I'm sure Ali and Louis probably held the spot as well (even though they all really had a lower weight fighter that should have been #1). All-time, I have Ali just barely inside the top 10, 8 being the highest I rank him. Louis is inside the top 20. Lightheavyweight, I know Roy Jones was #1 P4P but am not certain about others. As McGrain said, Langford is the highest rated fighter that fought there (#2 on my list), but of the fighters who are known for their work there, Charles is the highest and is always #5 or #6 on my list.