Made the first trim and pretty close - the vertical uneveness is due to the cowl lengths not being equal. Bit more sanding. Filed/sanded the joggle/flange to get a better fit ready for pilot drilling the screws.
SCREWS. DWG 48 Detail C shows 3 screws and spacing of 1 1/8" . That must be for an older cowl because you can only realistically fit two screws. I went for #40 as per the plans 0.45" from edge and bottom and one inch spaced and that seemed to work out fine.
