Spinks was. Qawi may have made the fringes just prior to their actual fight. McCallum may have made the bottom at some point. When he beat Curry he would have been close.
There was no 'p4p rating' back then. There was some list once a year at the end of the year in one edition of Ring magazine, for fun. It's all fantasy anyway. Not real.
So I've found McCallum at #8 in World Boxings list in 86. Curry was #1 and this was before McCallum beat him so Mike would have been in the top 10 plenty of times. Leading into the Tyson - Spinks bout Boxing88 has Tyson/Spinks/Holyfield 1/2/3. Spinks was in the 10 for years and years considering he was way up there as a heavyweight as well.
Michael Nunn following the Kalambay bout was considered lb4lb #1 in KO magazine, citing Tyson being rocked early by Bruno.