Hi Rob! Neither the drawing nor the photograph in the instructions is correct either.
View attachment 324851On Dutch ships, the garboard strake and the one or two strakes (depending on the ship) following it, extended all the way to the end of the sternpost. This was done to provide extra strength to the sternpost on which the rudder is mounted. This would prevent the rudder from shearing loose from the ship in heavy weather.
View attachment 324857
Here you can clearly see the bottom two strakes extending to the end of the sternpost.
Whether you have to try and change it or leave it like it is, is up to you.