Same thing happened in the United States -- it is next to impossible
to find any coins from before 1964, because they had all previously
contained silver.

For the sake of precision: that's dimes and higher coins, from
before 1965.

What is/was the situation with Canadian coins?

Pretty much the same. For coins of 10 cents and up there was a rapid
transition in 1967-68 from 80% silver to 50% silver to no silver.

ObRail: when I returned to London in 1975 for the first time since I
was a baby, you could use a payphone for 2p and ride the tube for 5p.
Over here the corresponding prices were 10 cents and 3 trips for $1 --
about 4p per call and 14p per trip. But in both cases, ours were flat
rates while yours were minimum charges (and 5p would only take you about
3 stops, after which the next fare was 10p).
--
Mark Brader, Toronto "Ever wonder why they call the screen
a vacuum tube?" -- Kent Paul Dolan

My text in this article is in the public domain.