Looking at the magic string "1.7 20120927", I guess your device comes from
ArtaTech (i.e.
www.onyx-boox.com a.k.a. "Onyx Europe").
I'm afraid you will need to talk to them directly.
I looked at my device which runs the
Mixed Firmware for I62/I62e/I62HD/A62/A62s/M92/M92s ArtaTech devices, but there is no Greek keyboard either (and that probably means that the
Booxtor's firmware lacks Greek as well).