Richard, I bought my wife a car just like your 78 Diamond Jubilee in 1990. It was our first TBird and she had two car seats in the back. I bought it for $2500 from a body/paint guy who had just re-finished it. His girlfriend was so upset that he sold it that I sold it back to him for $2500 three years later and bought my wife a SuperCoupe (...dangerously fast car.) Story is that the guy with the 78 parked it behind his girlfriend's house and a tree fell on the roof, caving it in. He fixed it!... and sold it.