Help me find my son?

I certainly think you should leave well alone - you have to draw a line under this the sooner the better. If you put posters up I think that is a cruel way to find anyone in these cirstances. Perhaps and possibility is big that he has not been told and has no recollection of his first two years. You could open up a whole can of worms and destroy what his adoptive parents have led him to believe. Whatever your cirstances were they have now been taken over and dealt with by his new parents and the boy. Pyscholigal damage is to dangerous to mess with and could happen if your instistance of finding him continues a risk definately not worth taking.