Digital UK's search was designed to show that even the oldest TV sets can be converted to digital with the addition of a set-top box.
Conducted in association with the Daily Mirror's We Love Telly supplement, the competition drew 100 entries.
Marconi was one of the biggest selling TV brands in 1936, a time when no TV sets were made outside of Britain.
Today there is one TV set factory in the country, the Toshiba factory in Plymouth -- 99% of TVs are made overseas.
The owner of the winning model was also given a new digital television.