They are a smaller, niche motorcycle company still in business, but I do not believe they have had an ATV for many years. In the US (not sure about Canada) the company SSR Motorsports sells a 250, a 300, and a 450 OEM'd by Asiawing, but I doubt they can or will help you on parts for an ATV. I would try to contact them directly:
http://www.asiawing.com/