Find Ancestors

Im trying to find my Grandson the last time i saw him he was two years old,hes my next to oldest son child but his mother died when he was just 2-3yrs old and her parents kept the boy as my son was,nt married to there daughter,and they made it quite plain they did,nt want me to see my grandson so rather than cause any trouble i left it at that,but wrote afew years ago to the g,parents asking if they had photo of him which i could have also explaining i was,nt causing them any distress,but they never replyed,and there still living at the same address
on my grandosns birth cert hes David Andrew Malcolm Williams,but on the bottom of the birth cert its got adopted,he will be 29 this year and never aday goes by when i think of him ,i do have the address of the other g,parents who he lived with but hes no longer there so mybe he got married,someone told me he had been in the army,but dont no what to do next,it was Tuebrook Liverpool L13 thats the aera,thank you for any help
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