THX for the screen shots, very helpful 
In my case (with an old Transcend 1 GB USB drive and vfat file system) I do see only an eject
menu item (not an safely remove drive as in your case - I have no idea why it is missing - I have nemo v3.8.5).
And: Eject does work (checked with mount in the terminal).
Note: The Portfolio file manager does not offer any way to “eject” an USB drive so I prefer nemo.
PS: This solution is also a candidate for the wiki (I have requested edit rights today to update the wiki).