We threw some cash at this one and paid the 430 dollars (more or less) for A DNA test on December 17th. As of today we checked the status and he was approved and his passport and card is being printed.
What you said is so true, so little information regarding this. After we went for the test, I was finally able to speak to my cousin who is an immigration attorney. He said this has been going on but no rhyme or reason. He said if you cannot pay for the DNA test, you can send in as much info you may be able to find, what they say in the letter isn't an all inclusive thing. He's had clients send in pictures I've the years, school pictures, other possible documents, things you may have together, like YMCA membership cards, health insurance etc.
It's upsetting that we have to go through this after all the years we go through legally paying through the immigration system. They allow us to bring out children on visas, pass medical exams, submit birth certificates etc and then for our kids, it isn't enough. Makes no sense. If I can help you out in the future, just let me know. Best of luck.