Title question.

I hope someone can provide me with some advice. I've just closed a deal on a non functioning, but restorable 65 A Body, (complete) located in near-by Oklahoma. The seller bought the car in the same condition in Washington, and trailered it to Oklahoma. The Oklahoma buyer and the Washington seller, both signed the Washington state issued title, consummating the sale in 2006. (The car was last registered in 1998) The Oklahoma buyer never registered the un-drivable car nor processed the title. I'm planning on bringing the car to my place in Arkansas. The Oklahoma seller seems to thing that it may take as much as $500.00 to make the title to where I can title it in Arkansas???? If I have a valid bill of sale from the Oklahoma seller and the title with the signatures, that should be all I need???
Norm