I am using version 56. In anticipation of having to update to Firefox 57, I am reviewing my present set up and trying to work out what I can keep and what I will lose. At present the menu bar is hidden and I am able to make it appear and disappear with the ALT key. I have searched through Classic Theme Restorer (which will not become a web extension), Preferences and through about:addons but can't find anything which allows me to show and hide the menu bar (excluding the View option which I don't need to use). I have the search bar on the menu bar as well as bookmarks. I am hoping someone can tell me what setting or control I am currently using to show and hide the menu bar.