Is there a proper way to document a complete restoration of my 69? I have to replace almost all the sheet metal, but I am specifically worried about the Dash and Firewall and remoing the VIN and Trim Tag. I car in a non A/C car and the passenger side cowl was completely rusted away so I did not find the hidden VIN there. The upper cowl has to be replaced, but the hidden VIN is there - but very rusted. Once all these parts are replaced, it is going to be obvious the VIN and Trim tag have be removed/replaced. How do I go about proving they are the originals - even though there will be no hidden VIN's left?