Vincent
Overview
1955
Phil Vincent made some of the most desirable British motorcycles of the 1950s. When sales of these began to deline he experimented with a 3-wheeler, a 2-seater with no weather protection powered by a 1000cc V-twin Vincent engine driving the single rear wheel by chain. No production resulted, and Vincent went out of business in 1956.
Source: Nick Georgano / The Beaulieu Encyclopaedia of the Automobile