Think I've got a bit confused with this one.
I have thirteen clashes.
Coordinates from BLHC are (across, up):
(4,1), (5,1), (8,1), (10,1), (6,7), (3,9), (5,9), (1,11), (3,11), (6,11), (4,13), (7,13) & (9,13).
If these are correct then how is the appending achieved?