See History of Gwydir Street and Buildings in Gwydir Street.
George Pledger Benstead lived in 17a Gwydir St in 1904 (see Spalding directory).
There is a memory of Hubert 'Ben' Benstead in 2010. He was born in Gwydir St in 1910, but unfortunately doesn't say which house! In 1913, there was a Benstead living at 5 Gwydir St, 17a Gwydir St and 40 Gwydir St. The memory is given under 5 Gwydir St.
Some research from Lyn Harding:
"My great great great (I think!) grandfather, John Clarke, lived and died at 17A Gwydir Street. He was born in Barrow in 1817 but moved to Cambridge and worked as a coach painter according to the 1851 census. At that point his family lived at 72 Adam & Eve Row, Cambridge. The 1881 census shows them living at 17A Gwydir Street. He had four sons John, George, Thomas and James and one daughter Jane by his first wife Sarah. and then Arthur and William by his second wife Susan Willimot who was his servant. After she died, he married his servant Susan Willimot, and had two sons, Arthur and William. He died 10 March 1890. One of his sons, George, lived at No. 19 with his wife Mary Ann Murdock. Another son, also a coach painter, moved down to Kent and died in the Bromley Workhouse in 1908."
From Capturing Cambridge:
HISTORY OF 17a GWYDIR STREET