How to get floor plans for older mobile homes

So we have bought a property up here in British Columbia Canada. Its a 1974 Safeway 12" wide. I have been trying to find a floor plan or blueprints, design plans, or structural info on the mobile, but cannot seem to find anything. Does anyone know where to look or could point me in the right direction?

We’ve had luck calling manufactures that are still in business. Just call and tell them you are looking for a floor plan for a 19xx home they made. We’ve not had success on homes where the manufacturers are no longer in business.