For example, if I were actually concerned about a plausible alternate history here, I couldn't call this thing a zeppelin, nor could I name it the Andrea Dorea, because there would be no Andrea Doria, nor would there be a Ferdinand von Zeppelin. Nor could I have the Shakespeare and/or Marlowe quotes I've used in a couple of these. Nor would there be any reason at all to have a Victoria or a Napoleon cognate, all of which figure in my setting. As does a French revolution, and a city of Boston, and all sorts of other things that wouldn't actually exist, or if they did, would exist in unrecognizable shapes and sizes.
Also, the names of everything would be different, the languages would be different, just unimaginably different. And that conceit where familiar historical persons show up slightly recast? Never happen: they'd never get born.
But since what I'm actually writing is fantasy, not any academic exploration of how the history of the world would be different if magic worked in certain limited ways, I don't have to worry about that stuff. Because I realize just how ridiculous it would be.
See, and once I start thinking about all the things I can't do because the world would be different, I never get anywhere.