You just can not compare the 63 to this car. But really sorry for your lost. But I hope you get a fair price for it and you can purchase the car back from them to sell off parts and such.
Why not? 2 years difference in age won't make a whole lot of difference? Difference in the red one being a V8 and his being a /6 will make little difference. The red car is an all original, low mile, original condition vehicle. His car is/was the same thing, but 2 model years older. Finding comps on 60ish year old cars isn't like comparing totaled 2020 Dodge Challengers.
