For 2 uncomfortable years between 1974-1976, Iron Man had a nose.
It was due to a miscommunication. Stan Lee no longer worked at the Marvel Bullpen regularly, but he often visited the offices, and due to his stature, his every comment was considered law. Sometimes these were miscommunications or rules on good practice taken literally. For instance, he critiqued someone using green as a background color in a panel – so the rule around Marvel was “never use green as a background” when what Stan meant was to never use a neutral color that didn’t make the foreground pop – green could be used in some circumstances.
Likewise, Stan critiqued some George Tuska art of Iron Man’s facemask because he felt it should be contoured, it was too flat to overlay over a human face, so he jokingly asked, “hey man, where’s his nose?” Since this was Stan Lee, this one joking comment was misunderstood to mean they had to add a nose to the Iron Man helmet – or else. It lasted between Iron Man 68-85, before Stan returned, was absolutely horrified Iron Man had a nose, and told them to get rid of it.
This was the era however, that Iron Man had a Mego figure, so it had a nose.