I have seen physique guys claim around that 3G+/wk + low GH dosages for competition.
Would the dosages for 70s guys be less due to them being less lean?
Hard to know because it was so taboo and frowned upon to share these things back then.
It ruined the sport and the Weider's and other promoters asked people to never speak of drugs.
I know a guy who was there (Gold's Venice) back in the 70's and said it was an ampule (or two) of each compound a day and as many orals they could handle without too much acid reflux. Guys shooting each other up in the locker room before training sessions and dudes with a large bag of Dbol handing them out like candy. Remember many of these guys had Doctor supervision, so if things got out of whack, they reduced their drug usage quickly.
Also, most guys only used a high amount for a few months a year. They would ramp up their usage coming into a show, growing into the show as the way most guy did it. It was common for guys to take long periods off gear to clean themselves out.
Obviously, everyone downplays the "golden era" as it has a sort of cult following of men who want to believe it was achievable naturally or on minimal amounts. Human nature will always prevail as all narcissistic mean and "athletes" have the "anything to win mentality". You think if these guys got big on 800mg of Deca a week they didn't double it? Shit was cheap from Mexico. Hell, most of these guys sold it. Part of the Venice scene being what is was is due to its proximity to Mexico and easy drugs.
Drugs today are no weaker than those of yesteryear, in fact most of them are probably stronger. Powders are so cheap these days you can make a vial of Test or Deca for less than $5.
The gear i get in Mexican pharmacies is top notch stuff. Even the UGL stuff from a good source is high quality gear. It's so easy to make quality gear these days. The bathtub brew guys have been gone with the wind a decade ago.
Like all things Old School people want to preserve it as some sort of utopia and the "good ol' days". When it was the same attitude of drug abuse we have today.