
I can offer one of my own. I used the name Johann Wittgenstein to replace Victor Mordenheim. I didn't like the name Mordenheim myself, because it sounded, well, a bit silly, even though I don't speak German and am only a little familiar with German names.
Now, many people think Frankenstein was inspired by real-life alchemist Johann Dippel. (If you've ever read the book then you know that Frankenstein did not bring his creation to life with a lightning strike, but rather with chemicals.) Modern myths attempt to connect Dippel to Dr. Frakenstein, such as the story that Dippel experimented with cadavers, but these appear to be untrue. But there are two solid connections: one, as mentioned above, he was an alchemist, and two, he was born at Castle Frankenstein. Wittgenstein is the name of the castle where Johann Dipple died, hence I came up with the name Johann Wittgenstein to replace Mordenheim.