I did what you did and to cover the no wind season which is very long in Boston, bought a used Serenity which is just like new and beautiful. I do have a 10 meter sail if I need it. Liked your pictures a lot.
The questions is I found 2 holes on the back part of the stern towards the end ( over the word "...windsurfing"), they look like they were drilled into the board. The previous owner does not know what the heck they are for?
They pobably cause no harm but I worry they could leak. Any idea why they are there?