Its possible to cross the border to Laos only with a copy from the green book. because I change the engine and the book is in a office to transfer the number of the new engine inside the book. But I have to wait more than 1 week, normaly we starting on 14.01. my name is in the book and I have only now the copy. Last week the check on Thaiside was very easy they not control engine and frame number. Maybe someone has the tel phone number from the Thai custom in Meung Ngeun. That will be perfect.