some quick grammar help, please :)

I'm editing something for my boyfriend, and he ended a sentence with:

"and not one of them was without a bit of grime on them."

I changed the them to it since I think "not one" is the subject and is therefore singular. The character speaking has a European/Victorian background and an air of formality, so I'm trying to make the speech as correct as possible.

Does anyone feel that "them" is correct in this instance?

Also, after an ellipsis, would you capitalize the first letter in the next word, or is that just Microsoft Word trying to rule & reign over everything because it saw "a period"?

I'm on a deadline (tomorrow, essentially) so I would appreciate some input.

Thank you :)