Better read up on this:http://www.skepdic.com/texas.html
"Our fathers were both named John"
Not terribly unlikely with a surname like Johnson (and the usual range of typical Christian given names in that time period).
"We were both born in December (less than a week apart)"
Odds of both being born in December: ~8.3%
Odds of being born a week apart: I don't have the math chops, but the odds of being born +/- 7 days apart is not bad at all.
"Our religion is the same"
North American and the same religion? Christian, by assumption... Anglican, Catholic or Presbyterian, by chance?
"We both lived in Toronto"
~850,000 people lived in the Toronto area in or about 1930... out of 10,376,786 in Canada.
"Even our signatures are similar"
You both have the same name and your signatures are similar... doesn't that seem... more likely than not?
It's fun that you have so many similarities, but I wouldn't call the coincidences "uncanny".