Add an Attachment icon in the classic iconbar.
On big pages and when working with slow connection, one should have to wait for the whole page to downaload to get the "Attachment" link at the bottom of the page.
Even on small page, and fast connection, one has to scroll down for that action, while in the modern theme its only one click away.
Discussion
The real fix to this problem is to dump the special code for classic, and have one code to draw an editbar that contains an actions menu. The edit bar can be displayed as icons only (classic), text only (modern) or both. The actions menu will be displayed as a menu, or anything depending on the theme. In any case, I want to move the attachments from the menu to the editbar itself, because its not an action, its one of the page view: last change, history, attachments.
Of course it is an action :-p