Why do you suppose he never fought at the weight? Do you think he could have won a title there? Say he fought Benn or Nunn for the WBC or WBA titles, respectively.
He gave an interview after Toney II saying he wanted Benn, Nunn, Barkley or Eubank. Probably nobody let him 'in' because he was too dangerous for too little reward. Couldn't break in. His body punches could be career-shortening, he had no TV backing, would've been seen as old and fat but able to **** them up.
Mike Went sharply downhill after Toney II, I think. But perhaps a big fight at SMW could have kept his motivation going a bit longer, so that he didn't turn up overweight as he did at LHW. If so, I'd give him a good chance against particularily Benn (who was well stylistically suited for McCallum) but also against a so-so motivated and prepared Nunn.