The TNFS is working fine, but I would like to move files (not just whole disk images) around (upload and download) my Atari LAN and between the Altirra on my PC and other machines on the network. The following is my solution, but if there is a better way to transfer files across I'd be eager to hear it...

As I previously described, I have my wife's old computer "defenestrated" to LINUX MINT. I created a DOS 2.5 disk image (TNFS_transfer.atr) and put it in my PC's /TNFS directory with full access (chmod 777 ...) and owner set to tnfs (chown ...). It attaches easily from host 8 as drive slot (disk) 2:

To get files to move between TNFS and my LINUX/WINE Altirra installation I need to keep both a TNFS and an Altirra disk image, in my TNFS directory and my Altirra user's directory, respectively:

I can then copy the most recent TNFS_transfer.atr between the Altirra and TNFS directories (adjusting permissions and ownership for each location) when I want to move files between the emulator and other machines on the network. Networked machines can just use the TNFS version without further intervention. I have also made some bash shell scripts to simplify the LINUX side of things.

If anyone has a different way, I'd love to hear about it. Otherwise, thanks again for dropping by.