I saw a similar programme showing how these guys kept the old classic cars on the road. The main thing that has stuck in my mind was the way they took panels from one car and just "panel beat" it into a different shape to fit another car. They showed 2 guys cutting the roof and boot lit off an old huge cruiser and because the "doner" steel sheet was relatively flat they said they could make anything for anything from it.
All they had to work with were leather pads, wooden mallets and only their own hand made panel beating tools.
It was amazing to see. I'm sure it must be somewhere on Youtube now