Plus, Happy's much bigger and broader-faced (not skinny). So, in conclusion, totally stumped.

I only thought of Erwin because seanchai and I have been talking about how much better Fraction's storyline would be if the blast-from-the-past villain were Clytemnestra Morley coming back to seek vengeance/justice for the death of her brother, rather than Stane's Villain-Sue kid with teh l33t hacker skillz - it would tie in nicely with Tony's ongoing guilt/issues over Happy & Sal's deaths, given that Erwin was also a friend of Tony's who died because of his proximity to Tony. And she's not just a computer scientist - she's got close familiarity with Tony's work, so you could have her plausibly cracking Tony's modified Extremis.

Maybe Clytemnestra could hook up with Maya and they could have hot lesbian scientist sex.