Dear Alexandra,
Hello, my name is Arthur Parslow,
I think that the bakery where your Grandmother may have worked in was B.B Grout Ltd, 101 High Street, Canvey Island, Essex SS8 7RF, (Tel: +44 (0)1268 511245) as I am sure this was the only bakery on the Island at that time, I say this due to the fact that my father worked in this bakers. His name was Arthur Samuel Parslow (But was called Sam) he may have know more but unfortunately he passed away a few years ago.
Our family lived on the Island by the lake at Vadsoe road and I was a child during the floods, I was born on the Island (1949) and I remember we all sat on roof of the bungalow with the water up to the gutters of the house at night, eventually the Army came and took us off in a rowing boat, I remember that day well, as it was my sisters birthday party (1953) the cakes and jellies were all lost.
But we survived

, we spent the following year in London, before returning to the Island, when we refurbished the bungalow.
Maybe since the B.B Grout which is still on the Island may have some records from back then, my be worth a look as I remember it was a family business.
I still have family on Canvey Island, a younger brother, an older sister, and others on the mainland in the County of Essex.
Lots of Luck,
Arthur Parslow