Grant has led us to some very useful information. There is a section that clearly spells out the regulation that is often interpreted differently by different MOT officers.
http://www.mto.gov.on.ca/english/tru...-faq.shtml#a16 I have printed a copy to go in each of my trucks for roadside reference if needed. It would seem that a considerable load can be carried legally if carefully placed on the trailer.
It is worth noting as well that, while they do not announce it, most weigh stations leave their scales on when they are not open & do not mind their use. I will be doing so again soon.