Hello Kirsty

You need his marriage certificate to establish the name and occupation of his father. This should help you get back another generation. Here is the reference:

Marriages Sep 1933
Redman William G Thomas St.Geo.H.Sq. 1a 1338

Make sure you get the certificate direct from the GRO (www.gro.gov.uk). Third party suppliers will charge considerably more than the statutuory fee of £9.25 for a much poorer service.

Caroline