Hi Daz
You are lucky to have found the birth cert of someone who was adopted.
Usually, unless you know the name at birth and the name after adoption, you can't always match up the 2 names and the relevant entries in the birth index and adoption index.
Of course there are many scenarios surrounding adoption. He may have been adopted by someone within the birth family which may result in his name not changing.
To find an adoption certificate which will show the names of the adults who adopted him, you need to consult the GRO adopted children's index on microfiche, but it isn't online. The fiche are located at 7 places around Engand & Wales.
Dawn