I own both the book of Valin "the RCA Bible" and also an Italian edition printed 30 years ago called "the records of the golden age" for my choices and for documenting myself.
I believe that the Italian edition is more complete and reliable as it is written by a passionate audiophile as well as accompanied by beautiful images where the best and worst RCA, Mercury, Decca and the London counterparts are reported .... if you are passionate, look for this book now out of print but sometimes you will find a used copy for sale on ebay.