Gilkison's photos of the Spirit of Ecomodder were shot at fairly close range,so they're probably a 'fail' as far as true length.
This shot from Bonneville is from a little further away,but you can tell that the camera lens was at the beltline elevation which will also not represent the vehicle at true length.
We'd need long telephoto images to approach 'technical drawing' accuracy.Something I'm not equipped for.