oh, and @jdd - MTS Videotex Client for C64 looks like it can load arbitrary #NAPLPS that you can put on the disk

Videotex – NAPLPS Client for the Commodore 64 Archived — http://jammingsignal.com/2018/01/10/videotex-naplps-client-for-the-commodore-64-archived/

Of *course* my friend Leif found #NAPLPS / #Telidon software for the C64 ...