My thoughts.
One thing to consider is that these were working boats, not sports boats, and were built for durability, even in storms. They carried a lot of sail to make it home as soon as they had a good catch, while the fish was fresh, the boats were heavy (especially going home), they were also wide beamed (drag) and all this added up to a lot of forces going through the mast.The masts may indeed seem heavy. See pics of Reaper. NB the second pick also has mast shadow.
By contrast, racing boats, had more elegant masts and spars. Even though they also carried a lot of sail they slipped through the water more easily, and did not go out in storms. Notoriously the 'J' Class, did not go out in storms. Sailing dinghies carry little weight and masts and spars are also lighter.
The other thing to think about, if it will be a working model, is the all up weight of the model, and the forces acting on the sail (and mast) when the wind gets up. You need to be sure that your masts will be strong enough. Remember your masts will be made of wood, not the much stronger aluminium tube that you see on many sailing models.