Yes, that folder has many folders for Model, Panel, Sound, Texture (several variations), everything I would expect to see in such a folder.
I even copied that folder into ...AppData\Roaming\Microsoft|FSX\simbojects\airplanes\ But that didn't solve the problem either.
Finally, I copied the folders from ...steamapps\common\FS\SimObjects\Airplanes to ...steamapps\common\FSX\SimObjects\Airplanes and that solved the problem
I wrote to the RealAir support email with a full description of the problem and what I did to fix it. I guess we'll see what they have to say. Apparently their installer doesn't know how to play well with Steam Edition.