They are very real. I got a couple of them from (former?) forum members. One was from a GBell auction. One was from an eBay seller whom I knew. Bank of Canada is not allowed to have them!
Fun fact: Since the serial numbers didn't go high enough in the 1935 or 1937 series to reach solid 7s, the first three notes are actually the first three $50 solid 7s printed by the Bank of Canada. It's hard to believe that it took 40+ years just to get three solid 7s. Now, thanks for the dwindling value of the dollar, we get new ones every couple of months!