The problem with Toponav maps is they are very detailed therefore very slow to display. Toponav is a vector based map as opposed Ozie which uses calibrated raster(picture) maps. If you want free 1:50K maps for ozie, you can check the canadian gov agency GSC (Geological Survey Canada) and download their maps for free. GSC offers in addition to the maps the calibration details. It is just a matter of converting the GSC maps + calibration details within Ozie.

I have done it. It works.