welcome to the garage Rob - the CDN numbering setup is totally different then the US system, so you won't find much on the details, but that number will be right if the plate hasn't been changed .... the first number being 1 should say it's a 1951 [probably first registered in 52], the next 4 are the series and model 17 83, the rest is the unit sequence number ... yes, the model would be a cab&chassis but would be 2.5T for 16000#
Bill