Professor Shirley Ann Brown runs the 21–year–old Registry of Stained Glass Windows in Canada (RSGC) out of York University. According to the site, its mandate is to "to locate, identify and record stained glass windows in Canada, both domestic and imported". The collected data is then made publicly available for research purposes. So far the bulk of the data comes from southern Ontario, but I imagine that many of you would be able to contribute some data from across the country.