There's no shortage of old-time HWs who were really modern CWs or even LHWs, so I'm not even going to bother attempting to list them. -Billy Conn first made a name for himself as a MW, but it was as a super MW-sized fighter that he hit his peak. It's even been alleged that he really weighed only around 169 (and not 174 as reported) for his epic 1st battle with Joe Louis. I would rate Conn as the best SMW-sized fighter that ever lived. -Lloyd Marshall successfully campaigned at both 160 and 175, but he typically weighed well under 170 even for the latter. My surmise has always been that he was a bit drained down at 160 and at a size disadvantage vs. full LHWs, so he would've been most ideally suited for 168. -Jose Torres looked great in fights where he weighed around 170 (vs. Pastrano and Olson), but as he gained weight beyond that he looked slower and sluggish IMO. -Lew Jenkins has described himself in interviews as essentially a "big FW," and he weighed just a pound or two above 130 for his early LW title fights. (Although a jr. LW class had previously existed, it wasn't being contested at the time of Jenkins' rise.) -Ceferino Garcia seems to have improved upon moving up from 147 to 160, but he really was only a jr. MW-sized fighter.
I dunno if it fits in the criteria of this thread, but could awesome would Eder Jofre have been at 122?
I've always suspected that he moved up from 160 to 175 primarily because his people saw an easier avenue to a title there.
There are quite a few fighters that probably would've extended their primes if a "junior" or "super" division had been available for them to move up to. I think Lionel Rose would've been one of the biggest beneficiaries of a 122-pound class.
I know he died before we could find out how he would do moving up, but judging by his frame I think Masao Ohba would have been perfect for 115.
The ones I thought of first were Marvin Johnson, Lloyd Marshall, Harry Greb and at 168. Ezzard Charles, too. He could've benefitted from a 190 CW as well, where I think he'd likely be the H2H goat (or Evander). Walker, Burley, Williams and Griffith woulda benefitted from a 154lbs division more than Robi IMO. Robinson's welterweight peak was actually while weighing like 144lbs. Although his best, or one of his best, performances he weighed 155½lbs, so who knows. Wilde could be as low as 105lbs in his prime. Borkhorsor would have been a destroyer at 115. Harada would've been as well. I actually have no doubt with day before weigh-ins that Spinks could make 168. Imagine that. Spinks vs Carl Froch
Even though he was known as a slow starter, Spinks would have destroyed Froch as Frochie does not have a single advantage and is too easy to hit.
Good shout on Burley, who was really a big WW/jr. MW for most of his prime years. Yeah, Wilde was actually undersized for a flyweight, as strange as that sounds. He was outweighed by over 10 pounds when he lost to Tancy Lee, which is a heckuva lot of weight for such a small man to give away.
No. Just no. Michael Spinks is not making 168, even in the 24-hr weigh-in era. I know he fought his first few fights weighing 168, but make no mistake, as a grown man/champion his frame was too big to be a supermiddleweight. If anything, all the modern era would do is make Michael Spinks a dominant cruiserweight after moving up from light heavy. Spinks was a much bigger man than a super middleweight like Froch. Obvious gap in quality, aside.
Given he was weighing in at 170 in 85 I'm positive he could weigh 168 in 2015. In his entire title reign, he only weighed in at 175 ONCE. Give him an extra six hours or so in the morning, and the clear advances in cutting water weight and it should be damn obvious that he can lose TWO pounds.