Mmmmm 750k Euros? I wonder who would advise such a price? An original 427 S/C certainly, but a replica, no way! If I had found an unknown Leonardo da Vinci painting 15 years ago, replaced the original canvas, and commissioned an "artist" to copy the Mona Lisa onto the new canvas. What would the new artwork be worth? It may retain the original stretcher and frame, but all the value would have been destroyed and I would feel pretty sick. Caveat Emptor.