Joe
Negotiate a good price. if you have already talked to the seller, as Jim has, maybe he will appreciate the small and specific market for the car and the passion that KF exhibit. Plus your commitment to travel to get it - may help in securing a usable price.
What kind of price is he thinking anyway? "Best offer" means a lot of things. WE know it's rare, and he might too, but that rarity interest lies mostly with KF geeks, not the Mustang and Camaro crowd.
$500? I think it's a $500 car easy because of Jim's specific notation of lack of rust. Rust as we know is a value killer. The rest of it can be done. Even if you hesitated in it's restoration, you would be doing the KF community a BIG favor by securing it.
I am moving June 13 back into Des Moines Iowa from a 3 car garage with room for another 3 cars around it to a 2 car garage and "maybe" room for one car behind the fence. I lost about $12,000 last year on these non runners that I would buy with high hopes, so go into it with a clear conscience. But it is a good one.