There are no more separate files for different font styles. In fact fonts have been simplified to 2 files whose location is defined by the SW_FONT_CONFIG environment. You cannot append your directory to it! You will need to copy the font_map and font_usage_names files to your customization directory and edit there. here is an example of adding a reference to the Hershey-Roman-Narrow font.
# placed in the font_map file DEFINE Hershey-Roman-Narrow type: Win32 size: SCALABLE comprises: Arial Narrow
You can test this by doing print(font.get_logical_fonts()) after restarting the session.