Dear Helen, don't know anything about Peggs in Cambridge that long ago, but..............my Uncle Cyril Pegg lived in Cambridge (13 Spalding Way) until his death about 4 years ago. He is survived by his wife Peggy, (Yes, Peggy Pegg) and son Graham, and daughters Julie and Janice. Janice and Graham still live in Cambridge. Julie lives in Cornwall. Cyril's ashes are now buried at the Cambridge United Soccer ground. he was a big influence in English soccer, and involved in rulemaking, refereeing, etc.. He was a coal miner in Doncaster, Yorkshire, in his early days. He retired from the Post Office (British Telecom, I think it was at that time).
His brother, (My dad), is Ken. He lives in Rhyl, North Wales. Both Brothers were born at number 44 Alexander Road, Bentley, Doncaster, Yorkshire.
Their parents, (my grandparents) from Bentley were Sid (or Cyril), and Ethel
I know it doesn't answer your question, but I thought it might be interesting.