I question that there were Canadian troops sent to Vietnam at any point, other than those serving with the International Control Commission 1954-73 or the International Commission of Control and Supervision 1973/74. I knew people who served with both of these organizations.
I served in the Army through the Vietnam period and there was never any discussion of Canadian units being sent to Vietnam. If so, it would have been big news inside and outside the Army during and afterwards. Its hard to keep the lid on things like this, and it would have been dynamite for any Canadian government to have done this.
There was some leaning forward in the trenches in the Army though. I recall a mock Vietnamese village being set up at the Infantry School in Borden for training. I also remember jungle type patrol training and use of the Minnissing Swamp, near Camp Borden, for jungle training.