I think you'd have to back into a value on something like this. The others should be able to put input for it.
For example (only), completely done, in decent shape, worth $25,000
Rebuild engines - minus $12,000
Repair upholstery - minus $1,000
Repair drives - minus $5,000
Detail, (Repaint Deck?) - minus $2,000
So, something like that. Brainstorm what it's worth, and what you think things would cost to get it to that condition. Then, how much are you willing to lose for the "Cool" factor?
I would also be very careful of the fuel tank. The older aluminum tanks are having issues with the new ethanol fuels.