I just rechecked Google Books to see if they would give me a better look at Volume 26.
They didn't.
But they give us Volume 27, 1911. And there's some good MFC stuff in there.
Bookseller & Stationer and Office Equipment Journal - Google Books
So, yeah, that's one way that Canadians got some American marbles. Maybe we could find some Argentinian marbles in such ads as well. But my brain is full so I will save the search for another day or let someone else have the fun.