I would be inclined to list it on
www.early911sregistry.org. It's where many of us longhood guys find each other. Condition and a fully intact engine will effect it's worth. To rebuild the engine is a 35 to 50k expense. I'm having a MFI engine built for a customer and it will be closer to 50 than 35. Any MFI parts missing will be somewhat expensive to replace.
Chris