On our last day in Winnipeg we visited the Manitoba Museum and I finally got some knitting content! They have one display on Mary Maxim in the Manitoba crafts section. She started her yarn company in Sifton Manitoba. That is all I can find out about the history of Mary Maxim. I remember that her catalogues regularily came to our house when I was a child and I would scrutinize them from cover to cover. The sweater jackes seen hanging in the display are the main type of pattern associated with Mary Maxim.