The Internet Archive would like to date about 70,000 of the recordings transferred from 78rpm records so far in the Great78Project. https://archive.org/details/georgeblood?query=NOT+date%3A* (oh, we just got another 2,500 dated thanks to a recent database dump of DAHR from David Seubert) We are particularly interested in ones likely to be pre-1925 since we will have one heck-of-a Public Domain Day party on Jan 20th (all are welcome virtually and in person) since all sound recordings pre 1925 will be going into the public domain (thank you Ron Wyden, ARSC, Public Knowledge, EFF, Internet Archive, and others) One source of dates might be The American Zonophone Discography parts 1 and 2, but the website says "All Mainspring Press books and CDs have now sold out." and discontinued. http://www.mainspringpress.com/ Not available on Better World Books or Amazon.com. I did not see it digitized from the publisher. If someone has these books would they be helpful in dating our records? Any other books you think of? We have the Decca and Columbia discographies and a bunch of others. Anyone willing to part with their books? Any help would be welcome. And anyone that wants to help date these disks could be most welcome as well. -brewster