Following documents I had
Original marriage document - I think it is KR3, my wife took a copy of hers and she only signed
Original KR2 from amphou office, so no need to sign, it was a two page document
Copy of KR5, sc name change document, signed by my wife
Copy of my wife's house book, wife signed
Copy of my wife's id-card, wife signed
Copy of my passport photo page, I signed
Copy of my Laos visa, I signed
Tuesday is a good day to visit, I went in front of consulate 8:30, four people before me were queuing.
Avalon 2 is a great place to stay, 500 baht, and within walking distance from the consulate, less than 1,5 kilometre.
Good places to eat: Lin's Cafe and Pilgrims Inn.
Use International Bus Mukdahan Savannakhet Mukdahan, bus station in Savannakhet is pretty close to Avalon 2 and consulate.