vegimite said "When you bought, took over the property there would have been a map and legal des:cription.
Using this as your base line, it should from the measurements be reasonably easy to locate the pins, if they are actually there.
I would 'phone the land titles office and ask if they have a more detailed des:cription and/or would advise of a means of locating your property boundary.
Just a thought in passing, would you not have to have a permit to erect a fence because it will be subject to byelaws regarding height etc.
Edited by vegimite, 2021-04-30 16:07:32"
Permits are not required for fences, although they are subject to by-laws regarding height etc.
https://www.brandon.ca/images/pdf/planning/Brochures/How_to_Build_a_Fence.pdf
It's possible no map or legal des:cription exists. Sometimes title insurance is purchased instead. That might apply here if the fence ends up being not quite in the right spot. It should be in the purchasing paperwork. If not, inquire with your lawyer.