J & M Stone Ltd.; 66 Upper Richmond Road, London

J & M Stone used brand names Emston, & Emstonette. They may have commissioned other manufacturers such as Champion to manufacture their radios.

Quote from Radio Radio page 166, regarding J & M Stone
"While many individual retailers carried on with single premises, the post-war years saw a great expansion of retail chains with firms like J & M Stone. (fig 273)and Civic Radio Services, who merged in the mid 1950's into a chain of over 100 Branches spread throughout the country."

Quoted from UKVRR,
"J & M Stone Ltd, was a TV and radio retailer with multiple outlets (in 1950, they had 64 shops and Max Stone was the MD – the “J” was John Stone). It was established circa 1929. They acquired Civic Radio Services Ltd, of Birmingham. Around 1960, all branches were converted to trade as “Civic”.
Emston and Emstonette was a brand used by J & M Stone Ltd, 66 Upper Richmond Road, London, SW15 (in the 1950s). I think the “Em” stood for Max and the “ston” came from Stone."