Trying to PULL THE TRIGGER

Unless he's willing to get the aircraft test flown, I'd pass as Alon's are pretty common in Trade a Plane. Being in Europe is a bit of an issue but not hurting myself is a priority.
IF I was sure I wanted this airplane, I would do a whole series of full power ground runs and run a significant amount of fuel through it. A motor quitting take off is a really bad situation. I guess if you had 10,000 feet of runway so you could climb high enough to either land straight ahead or have enough altitude to turn and return would be the ideal situation.

Ercouper’s
Finally found an Aircoupe I like (’66 Alon). Put down a deposit (since I live in Europe and intend to export it to the continent) and made the trip out to the USA to inspect it. Inspection went well, EXCEPT the recently top end rebuilt engine flamed out during our test run and could not be restarted.
A day later. Engine problem seems to be fixed by bleeding the fuel system, and the engine has been ground run twice since (both short ground runs).
PROBLEM: The owner is refusing to accomplish a test flight of the aircraft unless I buy the Aircoupe first!
Am I missing some sort of liability issue, or is this as irregular as it seems. I already purchased insurance for the flight (at my own coast) and will pay for the flight and CFI if required. I frankly don’t care who flies the ‘coupe so long as they test the systems and don't glaze the new cylinders. I just need the confidence that it passes a test flight before export.
Any advice on how to handle this would be great!
Cheers
Keith