I cannot recommend the book highly enough for both the facinating description of Zenith in the Trans-Oceanic period and, once you have reached the fanatic stage, finding the few errors, omissions, and creative restorations.
Is also currently available from Antique Radio Classified, Antique Radio Supply (see below), and Amazon.com.
Probably the largest dealer specializing in antique Zeniths in the world. Certainly the most extensive stock. Great Northern Antiques 5159 Bloomington Avenue South, Minneapolis, Minnesota. PO Box 17338, Mpls, MN 55417; phone (voice) (612) 727-2489 or (fax) (612) 824-3600
Antique Electric Supply, Tempe Arizona. 602.820.4643 AES web site Electron Tube Enterprises, Box 8311, Essex Center, Vt 802.879.1844 E-Mail Web Site
Antique Electric Supply, Tempe Arizona. 602.820.4643 (ask for catalogue) Antique Radio Classified 508.371.0512 - free CONUS shipping orders over $35.00 Web Site - look under "Marketplace"
Rec.antiques.radio+phono - generally prior to 1960 Rec.radio.swap - buying and selling, mostly modern Rec.radio.shortwave - general shortwave listenin