How to refresh a project from the file system?

I am using Android Studio - based on IntelliJ IDEA - so I ask this question here:

I was trying to convert a former Eclipse project into an IntelliJ project by "importing" it as Eclipse project.
This doesn't work! It only copied over the java files and ignored most others, esp. the manifest, the res folder and at least a dozen of other important files & dirs.

Since this didn't work I tried to set up the project manually. So I let IntelliJ first create a new Android project to have a "template" and then copied all those files that the former "import/conversion" had left out to the corresponding places taking the newly generated project as pattern.

But IntelliJ doesn't seem to take notice of all those added files! In Eclipse a "Refresh" would synchronize the internal/cached view with the actual situation on the filesystem (which would make such externally added files appear in the project).

In IntelliJ I tried File => "Sync with file system" but to my dismay that had no effect whatsoever! I then consulted help and then googled and apparently that command "Sync with file system" should have exactly that intended effect - but it hasn't!

So, how can I teach IntelliJ to take notice that there are a bunch of new files around?