https://en.wikipedia.org/wiki/List_of_royal_tours_of_Canada_(18th%E2%80%9320th_centuries) Roy
Were there any special cancels used during the Royal Tour?
Roy probably has heaps of them. On the following site, apart from FDCs, there is a postmark from the Royal Train P.O. that might be of interest to you. http://postalhistorycorner.blogspot.com/2011/05/1951-royal-visit-to-canada-princess.html