Toy modder Jonathan Kuriscak made an intricately detailed steampunk Iron Man figure, along with Tony Stark. You can view several more pictures at the link.
Really, giving Stark a big handlebar mustache was a great decision and should probably be used in the next Iron Man movie, regardless of time period.
Previously by Jonathan Kuriscak: Star Wars Bounty Hunters from World War II
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Steampunk Iron Man