I first checked www.freebmd.com
which has English civil records, but didn't find a matching marriage for George and Mary. I did find their children's births, in Bromley, Kent. Civil records of that year did not often list the Mother's maiden name.
I found this death record at family search, that appears to be your Thomas, based on his birthplace, year, and occupation. However, it says his Mother was Margaret McCarthyhttps://familysearch.org/pal:/MM9.3.1/TH-266-11853-94732-64?...
Mary's death is in the same database, but unfortunately does not list her parents