Can you identify the boat that used this sail?

The Dutch North sea Missing Persons Bureau has contacted HBSC about a cold case of a sailor found in 1995.
The only clues are a sail with the letters "HB" and a few bits of wood.
The four blue triangles suggest the sail was originally made for a fibreglass boat called a Compis 28.   However, the Dutch police found the sail alongside some parts of a wooden yacht.
The Dutch police think that the letters HB were added to the sail later by hand stitching and/or with a home sewing machine.
Can you help? Email hernebaysailing@btconnect.com if you have any suggestions.