Trans-atlantic narrative voice

[sushidog.livejournal.com]

Hi all,

Quiet around here, huh? But I have a dilemma and I' really like to hear your thoughts.
I'm writing what I hope will become a novel. It's made up of two intertwining stories, one of which starts in the United States and the other in England, bot in the mid-late 19th century. It's told in the third person, so the narrative voice is reasonably neutral, although I'm trying to keep it in keeping with the time. But I'm not sure what to do about the language divide. For example, when the story is following the American character in California, should I refer to autumn (I'm English, so that's my natural inclination) or to fall, since that's appropriate to the setting? If I refer to lucifers rather than matches, is that going to sound anachronistic because it's a piece of English slang rather than American? I'm not talking about the characters themselves using those terms here, but about the third-person narration.

What do you think?