Hi Gary
Making the balsa one piece is the better way to go.
If you shave off too much, use builders bog for filler.
A rough wood file is tool for shaping.
The bow is the hardest area of the hull to shape.
I am on easier street, I was given the fiberglass hull !!!
But it's taken 10 coats of primer/filler/undercoat to get waves out of the hull.
Harry