Half brother put up for adoption.

In the Uk you cannot "look" for someone who was adopted. You have to wait for them to find you! Make yourself visible, don't change your surname to something they won't be looking for. (I helped my man find his bmum who was using HER mothers maiden name! Not terribly helpful.) register on sites like this where they can find you if they are looking. You can register with NORCAP so that if your brother looks for you then your details will be there for him to find. And if you find each other TAKE IT SLOWLY.