User blog comment:Nausiated/Project 11/61: Iron Clad Continuity/@comment-4651179-20150214204240/@comment-61022-20150214233018

Yeah I noted that with a lot of the stories written after they established Tony as an alcoholic they started placing his drinking problems earlier and earlier in his timeline. Although it looks like I missed the story in Iron Man #500.1 during my first pass through (which is not surprising since I'm using the Iron Man index trade and the Marvel Chronology Project as references to help me pull comics to read) So there are some things I've caught (such as the "Secret Origin" story and the stuff from Original Sin) but others I've missed. I'll probably catch them when I come back to Iron MAn later.

As for his alcoholism, some stories that show him as an alcoholic earlier show this during his early years as Iron Man and with the Avengers. Usually this drinking was done in private. So that could explain the absence of him drinking in stories that were published in the 60 through to the 80s (other than the obvious fact that the Comic Book Code probably would not have allowed stories about an alcoholic super-hero during it's early days when comics were heavily censored)