Are you implying Reg was on anabolics?
Reg Park didn't use anabolics in the 1940s 50s, nobody did. They couldn't have, as Metandienone (marketed as Dianabol), was simply not known as an anabolic until the 1960s. Today there are other anabolics but back then none were known until it was discovered Dianabol worked as such. It is possible Reg Park used anabolics later on in his career.
Here he is posing with Arnold. Arnold is a bit bigger in terms of muscle mass but it is about the same.
I'm not going debate who is and isn't on steroids. But they weren't known until the 1960s, hence Mr. Olympia. So bodybuilders like John Mcwilliams who achieved 20 inch arms did so without roids, believe it or not.
Here is McWilliams from a 1950 article about his arm size:
1950. Steroids weren't known!
I have to wonder why it is that you scream steroids for Reg Park, Timber, when our knowledge of anabolic steroids precludes the possibility of 1950s bodybuilders using them.
Guys like Reg Park were exceptionally gifted genetically, plus applied training principles that work for natural bodybuilders. Many bodybuilding routines are designed for guys with steroids.
Besides, Mr. Olympia comptetitors have never denied using steroids. Arnold admitted he used them his whole life, and none of the other enhanced lifters who are serious do either to my knowledge. It just wouldn't be credible to deny it, given that most of the others do. The only ones that do are Youtube fitness channel clowns that talk about "one year natural transformations". Not all youtube channels on lifting are jokes either - there are good ones too.
Maybe you should do some more research on bodybuilding before saying these kinds of things, as they reflect that you are misinformed, if that is what you are saying.
If you are not correlating Reg with steroid use, then I agree with what you are saying about the fake natties.