I found some of the "then" photographs in multiple books and collections. Those I have not noted where the photos appeared. I have credited other sources of specific photos where needed.
A major source of phographs was the San Jose Historical Museum (Cited as SJHM). They have an awesome collection of old photographs! One example is "San Jose - City with a Past" by Kathleen Muller was prepared in 1988 as a membership premium by the San Jose Historical Museum Association. (Cited as SJCWP)
George Espinola's "Cottages, Flats, Buildings, and Bungalows - 102 Designs from Wolfe & McKenzie" which provided photographs of houses in downtown San Jose taken in the early 1900s. (Cited as CFBB)
Elizabeth Giarratana's book "Old Willow Glen" printed in 1977 (Cited as OWG)
"Reflections of the Past -- An Anthology of San Jose." This was a book printed in 1996 and prepared during Susan Hammer's term as mayor of San Jose. Lots of historic photos to pick from! (Cited as ROTP)
"San Jose's Historic Downtown" by Lauren Miranda Gilbert and Bob Johnson printed in 2004. Sadly, it contains many many photos of buildings that no longer exist. (Cited as SJHD)
"San Jose - In Inventory of Its Historical and Architectural Heritage" by the San Jose Historic Landmarks Commission, copyright 1975. (Cited as SJHI)
The California Room at the Martin Luther King Library on the San Jose State University Campus in San Jose (Cited as MLK). Their newspaper archives produced some nice old photographs.
Another surprising source for the homes that have survived was a project by Lynn Balunis (now Lynn Kelly). Lynn was a high school student at Leland High School in 1985, and produced a report for Mr. Sullivan's history class on the architecture of homes in downtown San Jose. Her report included some old color photographs. That report found its way to The California Room on the fifth floor of the Martin Lulther King Library in downtown San Jose, where I found it. I copied the photos and then found all of these homes still standing after 20+ years, some of them in better condition than when Lynn took her photographs. I have since talked to Lynn by phone (thanks to a visitor to these web pages who gave me her contact information) and she is delighted her high school report has been put to such good use. (Cited as Balunis.)