Awwww you just missed out Blue Paradise.
As for the dates, I'm able to confirm one fair only.
http://www.stichtingvansmurfenverzamela ... _data2.htm
But there will be certainly more of them, yet the dates haven't been confirmed. You could consider a trip to Venlo and spend some time at Frans' shop and visit some fleamarkets as well. Or what about spending some time in Utrecht. Tomorrow, the famous collectors fair will open again. And there's a lot to be found.
This fair takes place twice a year and it's really a must!
http://www.verzamelaarsjaarbeurs.nl/pers-bl