So...consider that the story is being told from one particular person's POV. This person is not American, but rather English and German. However, the author of the story is American, and another character in the story, whose POV will be switched to in a different chapter, is also American.

In terms of the differences in word usage between British English and American English, should each POV be presented in the character's frame of reference? Or should all references be uniform?

Example: In American English, the objects could be a flashlight, an elevator, or a truck. In British, they would be a torch, a lift, a lorry. Do I switch these usages (and I don't mean in a character's speech, but rather in reference to what he's seeing or doing) between the proper character's references? Or keep them uniform all throughout, resulting in American English references, as that's what I use?

English head: He pulled the torch from below the seat of the lorry.

American head: He pulled the flashlight from below the seat of the truck.

Opinions or hard-and-fast rules?