Recommended websites:

Lowther Loudpeakers Ltd The official Lowther website
Howes Acoustics A UK manufacturer of custom-built, hand-made Hi-Fi equipment, specialising in low-output single-ended triode amplifiers and high efficiency horn-loaded loudspeakers
Audiojumble The UK's largest event dedicated to the buying and selling of second-hand and vintage hi-fi equipment
Voxativ Loudspeakers for active listening
Retro Hi-fi A website specialising in retro hi-fi equipment
The Sound Of The Valve An Italian website featuring vintage and modern Lowther equipment
Lowther-America Distributors of Lowther Fullrange Drivers and Complete Systems
BD-Design A Dutch company specialising in horn speakers, including Lowther
Full Range Driver A website and forum dedicated to full-range driver loudspeakers such as Lowther, Fostex, Diatone, etc.
Horn Loudspeaker Magazine A blog for horn enthusiasts
Matrix Hi-Fi A leading supplier of new and used audio equipment A website from Hong Kong featuring Lowther equipment
ListenCarefully Blog Specialising in used audiophile equipment
B.V.W.S. The British Vintage Wireless Society
Vintage Radio Discussion Forum An excellent forum for British vintage radio equipment
Kiewa Valley Information on vintage Lowther, Tannoy and Leak equipment
Hong Kong Tube Audio Club An on-line meeting place for valve audio enthusiasts and collectors
Vintage Radios UK Vintage and Antique Radios/Radiograms, Service Data, Valves, Components and related items
California Historical Radio Society A non-profit volunteer organisation dedicated to vintage radio, based in San Francisco
Lowther Loudspeakers in Australia The Lowther Club of Australia
R.G.D. Museum The online R.G.D. museum, featuring many classic British radiograms