Thanks for the reply.
As a matter of interest, I was going through some of my Grandparents old photographs and found the one below which includes my Grandfather. Prior to marrying my Grandmother he worked as a hospital porter at (I think) St. Thomas's Hospital in Bermondsey. This particular photograph shows him in the second row, the man on the left. I think this photograph is probably from the mid-1930's.
What is more interesting, is the tall guy in the back row. In my opinion, he is the same chap that is shown in the group photo that I first posted (on the left of all the ladies). There are some others in the photograph including my Grandfather who also look familiar from the older group photograph.
It is entirely possible, that my Grandfather met my Grandmother through working with my Great Grandmother at the hospital.
Anyway, I think that solves the location and I would estimate the date of the original photographs to be mid 1920's, based on the aging of the tall guy.