Marvin Johnson Jim Jeffries (by the time of the Johnson fight) Tony Galento Rocky Marciano And Tyson had that bald spot just above his hairline.
I don't think any of those guys are hairless enough. Hell Marciano could get away with a toupee. Do you think Hagler could have worn a toupee; it would look like someone threw a shaggy carpet over a billiard ball.