Greetings,
I know the frustration you all are going through. I too was adopted ( in the state of Washington) and longed to fill that "hole" though I had the best adoptive parents imaginable.
Through a chance meeting I found an organization in Washington State called WARM - Washington Adoptive Rights Movement. They helped me obtain my original birth records and adoption papers. Though there was no warm, fuzzy reunion (my birth mother was deceased and there still seems to be a question on my birth father as I was marked "illegitimate" on the COB but had father's name in adoption papers) I was able to trace family with the info I received.
I just went to the WARM site and on their home page it says "WARM can search in all states for those with documented identifying information." You might try contacting them to see if they can help you work through court systems in Missouri.
http://www.warmsearch.org/about.htmlAs another person posted earlier the 3Ps I will say - "where there is a will there's a way".
All the best,
Lynn