Swissport also do the AOPA discount, though for LGAV this makes very little difference.
As of today Megara LGMG has a new restaurant on site.
Since 2005, when the GA airport of Athens commenced operations for civil GA, a hangout place was missing there.
It can be found in the Superior Air red hangar at the west end of the apron.
http://www.superior-air.gr/
https://www.facebook.com/superiorair.gr/
What Megara needs now is customs/immigration