Right Steve -
He'll get about half what he's asking, maybe.....
Since he doesn't talk about the motor, I assume it would need a good goin' thru, and it's not very clean (the engine). A couple of hundred spent here would up his chances of getting close to his price.
Of course a K1 tank is the coolest there is (make mine black, please), and it has real nice stainless exhaust.
The front end is imaginitive, but no big deal. 750 forks aren't that great either - they're made for a bike that weighs probably 150 pounds more than a 450, so they'd need some work, but he doesn't mention that.......
Steve does cooler stuff than that all the time.
Good shocks, ok seat..... coupla' grand, tops.
I wouldn't spend that much on it though, it still has a ways to go.