I am very impressed, vincent. You seem to have worked quite effective.
And I know what I'm talking about as I made my own fortress some years ago (doing my own moulds). It took three months of every spare minute I had (not mentioned painting).
You only should consider to change your "destroyed wall section". Taking the existant WM Siege Rules a destroyed wall section is between 4 to max 5 cm wide and could be in the middle, to the left or right of your 12,5cm sections. So maybe you should create some 4cm sections to exchange...
Great work,
Gerald