" I simply meant the calibre of athete running 10.7 in the 1930s woud likely be running close to 10 second flat today, and that's largely true."
No, it's not. Like I said, it is worth 10.4 FAT, 10.3 FAT at best.
Your example of Olympic placements is mistaken due to greatly increased talent pool and participation today vs then. As an example, if I was transported back to 1932 I could have medalled in the 100, 200, LJ, DT, obviously the Deca, maybe even JT if I got a bit lucky. Today? LMAO
Again I don't know specifically about Harbig, but consider this: that era was woefully undifferentiated, considering that he was apparently top 20 in both the 100 and 1500, as you suggest. Can you imagine!
No distance runner is ever going 10.7, and no short sprinter is ever going 14:30
That leaves long sprinters and middle distance. In my experience the chance of a 200/400 sprinter going 10.7 is far greater than that of a 1500m runner going 10.7, which is almost zero. Likewise, the chance of a 1500m runner going 14:30 is far greater than that of a 200/400 sprinter going 14:30, which is almost zero.
So IMO we are left with athletes who are excellent maybe somewhere from 400-800m.
You can already see the change in body type between 400 and 800m athletes, 400m athletes being visibly more muscular and heavier, and possibly even significantly taller. Forget about a 14:30 guy, you would be insanely challenged to find even a good 800 guy who can go 10.7. As has been pointed out many times, Lewandowski DID NOT, it was a different guy named Lewandowicz.
Of course I'm talking 10.7 FAT, not a flying hand-timed 10.7 (which is hard enough).
10.7 is no joke.
14:30 is also no joke, you have to have trained to achieve that kind of time, and you have to be primarily aerobic. For 10.7 you have to be primarily anaerobic. You cannot be both simultaneously.
What I could see is an elite 800-type training a year in the 100m and going 10.7, then training another year and approaching 14:30. I have my doubts about whether they would achieve either.