Would still need the A-pillars. And that's no easy task in itself. Why people think the only part of the job is cutting the roof off I don't know, there's a lot more involved.
I would just look at it as a parts car. Yes, it can probably be saved. But its going to take way more time and money than that car will ever be worth. And you'll need a donor car for those parts. And unless you find a wrecked Duster with a perfect roof and pillars, your donor car will be in better shape than the recipient.
Not sure how it is in Ontario, but here I could find a running Duster in way better shape than that and still pay less than what the sheetmetal on that car would cost alone.