Ummmm... yes! It's sort of "all of the above." From my point of view as the casual observer, it takes most of its inspiration from movies like First Men on the Moon and Chitty Chitty Bang Bang. I don't know if any of the founders of steampunk literature would admit to it, but considering they are our contemporaries, I suspect those films (and others like them) figured predominately in their childhoods as they did in ours. Or, barring that, the original sources... Jules Verne, H.G. Wells, and possibly to a lesser extent ERB. It hopped to the gaming world first via Space:1889 and then GURPS Steampunk (at the time I really despised the term steampunk, and during playtest tried like hell to convince the author to change the title, which is why I figure I didn't get playtest credit in that book... yeah... sour grapes... ). At the time of its printing, GURPS Steampunk was on the cutting edge. The amount of steampunk activity 10 years ago was nil compared to what you can find today.