You could go to Google Images and download pix of the profile and plan view of whichever aircraft you want , scale it to whatever scale to the printer and cut those out to use as templates -- cut the panels out of foam core , sheet styrene / ABS , cardboard ,balsa or whatever .
Spray paint the mockup the appropriate color .
That should be all you need . Just a flat fuselage and flat wings / stabilizers .
You won't need to worry about damaging a nicer model and you can make them up whatever size works best for the installation of LEDs