This is what currently is done in flightgears model loading stage anyway.
Modified Files:
Instruments/dme/dme.xml Instruments/kr87-adf/ki227_228.ac
Models/c172p.ac
-new better panel
-added lights and made them switchable
-doors can be open now (pick animation)
-added some liveries by Brett Harrison
-added paintkit by Brett Harrison
-converted liveries to png
-replaced radio stack with 3d-radios, DME and marker-lights yet missing
-minor bugfixes
-added glass shader with fresnel effect
still work on the interior to do like the seats, walls and so on...