I would say you're probably correct, my friend. Now back in the 70s the guys I knew that had condos at the beach and Corvettes but didn't work? They were hustling, i.e., selling themselves to old queens and the like. I don't know which is more disgusting, a buttslut or a pusher. But since stayroids weren't illegal back then I know they weren't selling anything but their butt.
I would mercilessly taunt them for being a manhoe. Every single one of them would say, "I'm not gay! I only do it for the money!" As proof of this, one guy even said he "never kissed a man so I know I'm not queer"... Of course getting fucked in the butt or smoking the wang isn't a gay thing at all so long as you're getting paid.
Bodybuilders, "competitive" bodybuilders, are among the laziest morons on this phlatt Earf. 
With all due respect The Scott, you speak in very demonstrative terms about your knowledge of something you have made clear you have never done/taken. That would lead me to believe that you were not in any circles or people that would know the truth....or at least share it with someone that is not doing what they are which was illegal without a script, btw. Steroids were just not on the "things we give a fuck about" list when it came to Police, DEA, FBI, Customs, etc. until they became a CIII schedule drug in '90
I don't know about going back to the 70's, but I can say with certainty that steroid dealers existed and did very well for themselves in the 80's. My former boss owned several gyms in partnership with a very very well known name in the gym and bbing industries. My former boss was partners in his steroid dealering (i just made that word up) with a very very well known muscle publication that no longer exists. My former boss came to owning those gyms with the previously mentioned very very well known name in the gym and bbing industries (whom he met while training at the Mecca) after he was indicted for conspiracy to distribute AAS and some other charges (money laundering & taxes IIRC) The very very well known publisher has written a story about how they would present everything they had for sale in briefcases. That story was published years after my boss told me that's exactly how they operated ("like businessmen" he said). Many many other great stories about those days that I was told by my boss, and some even better shit he left out that his brother told me about him and his dealering partner while we smoked some great bud together.
Anyone, that's been around a while can piece all this together, and figure out my post is legit and who I am talking about. Keep it to yourselves, or just give a wink/smile if you are one of those people.
Side note: Dr's, DEA, and FDA all had some representation that spoke against AAS being put into CIII category as it made no sense. If bbing mags were still around, an interesting investigative story would have been on why this became an issue for the gentlemen that sponsored/co-sponsored the bill...and more importantly/interesting.... who their donors were???
https://www.congress.gov/bill/101st-congress/house-bill/5269/cosponsors"Sponsor: Rep. Brooks, Jack B. [D-TX-9] "
"Cosponsor Date Cosponsored
Rep. Hughes, William J. [D-NJ-2]* 07/13/1990
Rep. Hoagland, Peter [D-NE-2] 09/05/1990
Rep. Annunzio, Frank [D-IL-11] 09/05/1990
Rep. Oakar, Mary Rose [D-OH-20] 09/05/1990
Rep. Hefner, W. G. (Bill) [D-NC-8] 09/05/1990"