IGI doesn't cover the period you're looking for in Bradfield. Sorry I don't have the Bradfield CD, but someone may be able to check for you and see if they are there, rather than one of the other parishes in Bradfield RD.
Bradfield PRs are available on CD from
Berks FHS price £10.35Bradfield St Andrew and Methodist Chapel (CD)
Includes: Bradfield: Baptisms 1539-1962. Marriages 1559-1989, Burials 1540-1952 and Banns 1799-1980. Methodist Chapel: Baptisms 1873-2002, Marriages 1921-2006 and Burials 1908-2006.
Adnams is a very common name in West Berks, so I doubt very much he's the Alverstoke one.