Copy files from Ubuntu desktop machine to headless server using SSHFS
SSHFS is a utility in Linux that allows you to make a remote file system available over SSH act as if it was inside a folder on your own system.
Click File -> Connect to Server. Select SSH for Service Type, write the name or IP address of the computer you’re connecting to in Server. Mu desktop machine automatically added a bookmark to the Places sidebar so I could open it later if I needed to.
The only issue I see is that I’m logged into the server file system as a normal user and have no good way to give myself root access (no sudo). In order to do that I’d need to add a root user.
Files can be copied by dragging and dropping between this window and other windows.