I have copied and uploaded the SVC 4.01 MFB ROM image to the Gemini 80-Bus Resources page.
https://glasstty.com/wiki/index.php/...01_MFB.ROM.zip
I also now have T-NET working and it took some sorting out. Both my Linux box and the Gemini have their serial ports defined as DTEs which is what I expected, however, the Gemini has the TXD and RXD reversed so neither a DTE or DCE but something of both. I have created a custom cable for now but will sort it all out and make it a proper DTE once I have moved house. Anyway the upshot is that I now have my Gemini networked to a Docker container runing on my Arch Linux box. This also works on my Mac, and Windows should work also.
I will create a Docker 'run' command that starts the server automatically and post it to Docker Hub and glasstty.com when I get chance. That way the server can just run under Docker in the background.