Quite so. The GENERAL boundaries will be shown on the LR title plan document. The (old) deeds may or may not show the boundaries in any more detail.
You can't scale off general boundaries though they may be helpful if they align to the physical feature on the ground (like a wall).
Please say a bit more about what you are trying to achieve.
I get the impression that you can't. Have had a neighbour put up a fence, rerouted to nick a thin triangle from my side such that I am no longer able to walk down one side of my garage, and destroyed the one tree I'd planted. Only found out when I returned the weekend after. Could not face the stress of trying to prove it. Especially when informed the deeds never hold details.