Hey Andy,
I am sure you wouldn't be interested in this, but if you ever want to sell just the engine, I would like to know about it. I too have seen this bike in the flesh and ever since I saw it I have craved that motor. I am sure it would be out of my price range, but if you ever wanted to sell the motor, maybe you could let us all know.
I also agree that the asking price is more than reasonable. All kinds of custom work done to many different components. Good luck on the sale.
Gilbert