My hardware works great, working on the software.
This is version 2 -- includes a Pico and an SD card and will let you upload PTP files. Can auto-switch over to the TTY mode and the attached wire connects to the reset line.
The buttons are standard tape-deck buttons + RESET + MENU
I didn't have a USB reader at the time so I bodged in an SD card adapter. Looks funky but it works.