Quote - I accept steampunk is a recent twist somehow but I don't get it. The definition of steampunk I read would make the original Frankenstein steampunk as well as a lot of other stories we know well. Most stuff by HG Wells, Jules Verne etc...

No, they don't count as Steampunk.  Shelley was writing science fiction looking forward (the fact electricity could cause the muscles of dead animals to twitch had been made not long before, and she was extrapolating), Wells was looking forward while Verne was either looking forward or writing what we'd today call a technothriller (20,000 Leagues Under the Sea being the main example here).

Steampunk has to be looking backward at that era, using the inspiration of Wells and Verne but looking at it with a modern point of view.  To use an easy example, writers of the time would be unlikely to use the "Wrench Wench" character (Agatha Heterodyne from "Girl Genius", for instance) whereas someone with more modern sensibilities would have no problem with the character simply because the idea of women as mechanics, or mad scientists, isn't something that's outside our acceptance range.