If when you arrive there and the engine is cold. If the upper rad hose is hard you may have head problems. The head problems these engines are noted for may be a bargaining point. Look at the condition of the engine coolant as well. Actually I probably would take along a cheap kit to test for products of combustion in the coolant on any of the early 603 engined cars. Now with a much newer head perhaps not so critical.

When I buy a used car I size up the seller first. To me it is odd but if I am not fairly comforatable with them I usually do not buy their car.