there were definite differences.  the 4ft model had raised panels, a different deflector, shape changes to the neckm and the spine was different.  the color also became greyish hues rather than green and blue.  Also, the secondary hull was a bit narrower and taller.  Overall, the ship just had a more staunch look to it.  Oh yeah, and the port nacelle was pointed a bit down, but i took some artistic license and fixed that. lol