Hi I`m from Belgium and I`m married to a thai girl too. I don`t know what the papers are for now cause they change it every time just to make life more difficult. Anyway if you really serious about this and wan`t go on with this I can only suggest that you go to your cityhall ask for all the information. They have it all they just have to look in their books. And to make everything secure just call the thai emabassy in Brussels and ask for al the required papers you need.
http://www.waw.be/rte-be/english/dao/eng_home.htm
Royal Thai Embassy
Mission of Thailand to the European Communities:
2 Square du Val de la Cambre, 1050 Brussels, Belgium
Tel. (32-2) 640.68.10, Fax. (32-2) 648.30.66
E-mail :
thaibxl@pophost.eunet.be
They will help you whit everything you need to know.
Friendly regards Beuk.