Looking at birth registrations, there is a Walter Freeman, jul-sep 1954, Grimsby district, vol 3b, p286. Mother's maiden name Short.
Can't see another one between 1952-1955.
If you think this is 'your' Walter, you can order the cert from
www.gro.gov.uk/gro/contents/certificates. The birth cert will give parents' names.
Hope this helps
Christine