Paul Sloggett told me that on the day Jock Macdonald retired from OCAD he dropped dead. According to Sloggett, Macdonald was mercilessly ridiculed for being an abstract painter by the other faculty. He thinks that Sandra Altwerger and Peter Ma may have studied with Macdonald, or at least, they would have been there at the time and may know some other people who did. (Going to try emailing both of them today.)
William Ronald worked at Simpson's, that's why they had their first show there.