Well actually the idea of extracting the old fonts did not work
While they have the correct extensions they must be encoded in some manner.
Adding fonts just requires (with the Kobo attached to your PC or Mac or ..) a directory called
fonts at the root level of the mounted device (ie the same level as the
.kobo directory appears). See
https://www.mobileread.com/forums/sho...3&postcount=10 for screen prints.