Probably by asking the manufacturer, but if he's no longer in business you might at least find earliest possible date from a history of the company or from a dealer.
Stanley Seymour has written: 'London - day by day' -- subject(s): London City Mission
Stanley Beard died in 2007, in London, England, UK.
Stanley Meadows was born in 1928, in London, England, UK.
Stanley Irving was born in 1908, in London, England, UK.
Stanley Caine was born in 1935, in Southwark, London, England, UK.
Stanley Haynes died in 1958, in London, England, UK of suicide.
Victor Stanley died on January 29, 1939, in London, England, UK.
Stanley Turnbull died on May 8, 1924, in London, England, UK.
Stanley Pavey was born on December 23, 1913, in London, England, UK.
Stanley Maxted died on May 10, 1963, in London, England, UK.
Stanley Dark was born on May 15, 1874, in London, England, UK.
Stanley Holden was born on January 27, 1928, in London, England, UK.