https://en.wikipedia.org/wiki/Isambard_Kingdom_Brunel
Brunels' achievements spanned both civil and naval engineering projects, and much like Musk he didn't so much invent something completely new, but innovated on existing systems. His work on propeller screws is very much in the same vein as Musk and the Raptor engine. Probably fair to say he was a larger than life figure in his day and a driving force during the industrial revolution.
I think with Musk, it's the lesser known achievements like the big battery in South Australia that elevate him to the level of Brunel.
https://reneweconomy.com.au/tesla-big-battery-outsmarts-lumb...
In an age where radio was new, where televisions were even newer, where transcontinental news took hours, days or even weeks to travel, the knowledge that the Nazis were engaging in mass murder was not readily available.
When allied troops liberated the concentration camps they filmed everything that they saw because they were concerned that without footage no one would believe them. Why? Because it was a shock, a shock so unbelievable in writing that only video and photographic evidence would suffice.
In hindsight being 20/20 it's hard to comprehend the blurred optics of the past era.
Moreover, the blood libel of WW1 was still a fresh memory, and so many who did hear about Nazi atrocities were skeptical.
The world would be different today if not for the photographic and video evidence.
Either way, that's not really my point. There are probably better "eccentrics" to compare Elon Musk to, that aren't so dramatically worse than Elon Musk. Perhaps Howard Hughes? There are some problems with that one too, but I think the rift between Elon Musk and Howard Hughes is probably narrower than that between Elon Musk and Henry Ford.