I think there may be a "terminology" problem with getting an answer to your question.
I, for sure, have never heard of a "daggerboard pusser" in all my 25+ years in windsurfing.
Is this the handle that one used to raise and lower the daggerboard?
Is this the seal on the bottom of the board that seals the daggerboard cavity when the
daggerboard is retracted?
Is it a cover over the top of the daggerboard?
What exactly are you referring to as a "pusser".
Hope this helps,