Well guys, here's the long and short of it...
It is a violation of Title 19, United States Code, Section 1595a(d), Title 22, United States Code, Section 401 and Title 22, Code of Federal Regulations, Parts 120-130 to send a stock outside of the US, as gun stocks are listed on the Department of Commerce, Commerce Control List, (CCL).
Don't ask me how I know these specifics

Maybe because U.S. Customs and Border Protection corresponded with me very recently. We had coffee together as we went over the six page document I received...
If you are out of the US, and want to purchase the stock, you will need to involve both an importer and an exporter, and you will need to complete the required documentation on both ends.
I continue to sell stocks to a Canadian sporting goods company who has engaged the services of an exporter in Washington state to take care of all the required red tape. I can provide the specific information in a pm if you are interested.