From older Canadian telephone directories at Ancestry.ca, M.A. Clark (no e) was listed at 67 Curzon Street up until the year 2001. In 2002, there is a J. Clarke at the same address. There is also a T. Clarke at 40 Curzon and an L. Clarke at 15 Curzon in the same timeframe.
There is an R. Clarke listed at 67 Curzon today with a current phone number available at 411.ca