scarf joints being prepped . NOTE : I placed the lower panel scarf joints at 48 inches of centerline . the manual calls the joints out at 15 inchs off centerline. The reason for this is that the material list calls for 3 4x4 foot pieces of metric ply . Since the metric ply was backordered at the time, I purchased 1 - 4x8 3/32 and 1 4x4 3/32 domestic birch ply . This puts most of the scarf joint over the wheel well - which is cut out for the gear doors .