Buying a 76 Euro Targa

[Jesset100]

A friend of mine is selling his 911 and he wants me to buy it for $3500.00. The catch is the engine is blown.
I've seen the car while it ran but not after he grenaded the engine so from what I gather from him the number 4 cylinder is what let go. (he doesn't speak good english)
All I wanted was the transmission but he wants to sell the whole car. Why should I buy this car? Is there parts on the car thats worth the trouble to part out besides the obvious bits and pieces ie wheels, gauges, whale tail, etc...