The Rider's Perpetual contains 23 volumes of
schematics. The volume 18 is copyrighted 1948 or 1949 (The volume 19 is copyrighted 1949). They could be ordered at: Alton H.
Bowman, 4172 East Ave, RD 2, Canandaigua, NY
14424-9564, USA. For your information:
Other big collections of schematics for the USA
are the books «Most-Often-Needed Radio
Diagrams», compiled by M.N.BEITMAN (beginning:
1926-1938 = Vol. 1) and after the WW2 SAMS Photofact.