In the beginning it says that this process will work for any kind of custom font files (not just Google).
However, I hit a snag.
After uploading my fonts locally to the Media Library, Leo says go back to Step 3 of the Google font helper. However, if you don’t use Google fonts, there is no step 3.
1. Add Font
2. In the Font Family field enter the exact font-family name you have in your @font-face CSS
3. DO NOT select Google Font if that option shows ( should only show if the name matches a google font ).
Once thats done and you Add Typography you will see your font in the list.