Comparing the two photos, there are quite a few apparent differences.
First, the bonnet hump is a different shape, the lights, whilst similar, are also differently shaped and on the puzzle car the front wings seem to have a rounded rollover, whereas the poor scrappy looking one clearly has razor edges.
I wonder if the puzzle car is perhaps the production model and the decaying vehicle the original 'mule'?
Or am I imagining the differences?