no way to correlate. when i could bench 3 for 10 i couldn't do 4 for a single. by buddy could do 4 plates for a triple when he could do three for ten. strength in one rep range could not be multiplied to a standard strength in another rep range.
first time i squatted 5 plates for ten Grant McReynolds (miss you old buddy) who was a former canadas strongest man watched and said i could triple 6 plates now. i put on a 25 a side on the 5 plates and it felt like it had doubled. i couldn't do a single rep.
but considering Animal was touring and wrestling every night, that was just another average workout, nothing special to him. i is unlikely that i met him at his strongest.
You're right to suggest that there is no way to correlate with complete accuracy/specificity. I have found that the one-rep max calculators have been pretty accurate for me...but I do understand that they are imperfect tools, and that we can't know for certain that they are accurate in their projected calculations.
That being said...I would have to seriously consider the possibility of someone who bench presses over 600-lb with relative ease as being a person who potentially could have been very high up there at the world level for the bench press had he specifically attempted to be.
Whether or not that would translate to being THE world record holder...that much I don't know. But it sounds to me based on your stories and those of others, about Animal, that he was way up there anyway.
I don't know what the top 100 raw bench presses were around 1990. I think Bill Kazmaier bench pressed around 636-lb in a powerlifting meet, and he was a multiple World's Strongest Man winner. So I'd be curious where Animal ranked as it was, globally at the time. If he was, say, #76 or something for bench press as it was...could he have gone to #7 if he had trained specifically to do so?
I guess we will never know since, as you said, the tools to project these things are not perfect. So we can only speculate. I just thought, since you trained with Animal, you may have been more confident one way or another about his potential in bench press.