Hello Susan,
What I have been able to find out is that in 1920 there were a number of address' linked to the Abbott family.
There was a Walter Abbott, Watchmaker, who had a home address listed as 53 George Street and a business address at 30 James Street, Cardiff Docks.
There is also a Walter Abbott, Jeweller, who is listed at 38 Blaenclydach Street, Grangetown, which is the same address the family was recorded at in the 1911 census.
Looks like Walter had two separate business concerns.
From the street/business directories they were listed at the same address as above in 1922,1924,1927,1929,1932 and 1937.
In 1949 he is listed at 7 Greenwich Road ,Canton as a home address, and at 11 James Street, Cardiff Docks as his business address.
The same address also applied for the years up to and including 1961. Regarding the maiden name of Gertrude Eleanor Steel, if you were to purchase her marriage certificate from 1902 that would list her fathers name and therefore her maiden name.
If you need any further help regarding information or records in Cardiff, you might like to contact me.
Best Wishes,
Paul Durkee.