I wonder if this is what is referred to as a "Spanker" class?

Perhaps do a search on www.ilse.nl (dutch search engine). Use the key
words "Zeilen spanker klasse" and see what it coughs up is similar to
what you have.
My brother has built one recently and races it:
http://www.weidema.com/theus/ -- click on "photo galerij" to get an
idea.
It that's it, I'd be happy to translate whatever page you need to read.

If it is a spanker, It can be a very cool little boat to sail -
congratulations on your find!

Remco