I would suggest that the problem your EBay seller faces is most likely the requirement for a US govt. export permit to ship this part out of the country. There are several lists of items that are controlled by the US government. Penalties for exporting illegally (without a permit) are severe and apply to companies and private individuals. If another person, a third party, picks up the controlled good and transports it over the border for you he would face the same penalties if apprehended between the mail drop and the Canadian border.
There are some informative threads on Hunting BC on this topic. Some interesting cases involving night vision goggles that you can google. I worked in the defence industry for close to 10 years and dealt with this on pretty much a daily basis. You would think that many laws are outdated, ridiculous and so forth, or don't apply to us, but remember this is government. Wink
Brownells does ship to Canada, and some Canadian gunsmiths seem to know the channels and may be able to help. Hope this helps
