This is what I handed in...
Copy of your front page of passport
Copy of your TM47? thing. The white slip stapled in your passport
Copy of your last entry stamp in passport
Copy of wife ID card
Copy of Tabien Baan (blue book)
Copy of Marriage Cert and Kor Ror 2
And most importantly, the original
marriage cert and Kor Ror 2 (it's the other piece of paper that comes with the flowery marriage cert.
Oh...and 5k baht
You and the missus sign each copy, and you are good to go.
Have photocopying across the road if I have ballsed up anything and they request more
Apologies if some of my terminology is incorrect, but you should know what I mean.
Good luck. Hope you're a drinker or enjoy going to dinosaur fossil museums?