To have or not to have....

Over at Language Log, Arnold Zwicky describes some seriously non standard use of have (meaning to own) and have (meaning to carry, to have with you) as concise and effective at disambiguating the intended sense:

They were supposed to do a half-hour of silent reading and write about it, but only a handful brought books. The rest... were allowed to write an essay on why it's important to bring your book. "If I write, 'I ain't got it; that's why I don't got it,' is that worth points?" asked one of three boys who taunted the young teacher the entire two hours.

Zwicky dismisses the own/have with me option as slightly off, semantically - since the student in this specific example would not be owning the book but just have it assigned it to him for the duration of the school term. Even accepting this fact, there are at least two options - one of which sounds perfectly fine to me, the other which I believe to be slightly non-standard in American English. If anybody cared to comment and give me their native-speaker intuition on either one of these....

The first one - which in my intuition sounds standard and evokes the right semantic framing - would have been to use "If i write, 'I don't have one; that's why I don't have it,". In this case the usage of an existential quantifier versus the definite anaphoric reference to the book evokes the correct semantics, at least for me. Does it, for anybody else?

The second one is even better, at least from my intuition, although I fear it may not be standard in American English. Any native British English speaker cares to comment on whether it is ok for them? So, how about if the language used had been "If I write, 'I haven't got it; that's why I don't have it,"? Is it still ambiguous? Is it non-standard English? Both questions are no's for me but the jury's still out. Of course, "If I write 'I haven't got one; that's why I don't have it," seems to be the best choice of all. Clear, succinct, unambiguous, and quite standard.