The book you asked about does not have an address for "The Commonwealth Press, Inc., Los Angeles, California." My online yellow pages/business directory doesn't list any "Commonwealth Press" anywhere in California. The company may have gone out of business, or changed its name, or become part of some other company. Sorry.
http://members.tripod.com/~ntgen/bw/comst_index.htmlhttp://members.tripod.com/~ntgen/bw/comst_index.html says "A History and Genealogy of the Comstock Family in America by John Adams Comstock, Del Mar, California, Privately printed for the author by The Commonwealth Press Inc, Los Angeles-California,1949 - This book is on-line at genealogylibrary.com and is also available at various bookseller web sites on the web."
T. J. AaRON (post 804, I think) just gave us the URL for this book online: it's at http://hammer.prohosting.com/~comfam/http://hammer.prohosting.com/~comfam/ The look-ups I've been doing in my copy seem unnecessary, now that we can search the book online.
I haven't been able to find any bookseller web sites with the book available this morning. Maybe if you search for the book online from time to time, you'll get lucky and catch the book when it's listed for sale and not yet sold.
I intend to give my copy of J. A. Comstock's book to Bertha Adele (Comstock) King's grandson. There seem to be no Comstock ancestors in my family tree, although my ancestors lived near yours in New England.