This is fascinating. On all the Canadian census forms the family is listed as Irish (with an immigration date). Family stories have it they were in Castletown on vacation and John Joseph came early. We could never understand how this poor family could afford such an extravagance. Maybe they were living there.

The names match census and other forms here. John Joseph lists Castletown as his place of birth on his enlistment papers for WW1.

Looks like much more detective work is needed on this end.
Thank you so much for this tidbit of information. That's what I love abt this type of research - it brings out the inner detective.