The Dubreq Stylophone™ was a runaway success in the '70s, not so much within musical circles (although they have been used by such luminaries as David Bowie, Kraftwerk and Pulp) but as a gimmick, a toy, a marketing success story.
Dubreq was founded in 1967 by three British workmates: Brian Jarvis (inventor of the Stylophone), and brothers Ted and Burt Coleman.
They worked in the Broadcast/Film industry, dubbing and recording film sound tracks, hence the company name - 'Dubreq' (presumably, the 'q' was used to add an air of European mystique)!
The company brought in jovial Australian entertainer Rolf Harris to help promote the Stylophone™. Rolf was a popular kid's TV presenter at the time and his almost shameless propensity for jollity and self-promotion made the Stylophone™ a huge success to the point where most people thought that Rolf actually invented the thing himself... he did not - he was merely a well-known face used to promote it.