Attaching the transom. The inner part first.
And the other two parts. I painted ahead of time because it would be too difficult to get a brush into the recessed areas.
The pieces were attached in a staggered fashion so that the top surface would be horizontal. This will allow the trim piece to sit properly on top.
The view from the back. 1/16″ x 1/16″ strips were added to fill in the remaining space. A little more work is needed to smooth out the area just below the transom piece.