This locomotive, built by Aveling & Porter, Rochester, Kent, who are better known for their traction engines, is a "cousin" of Quainton's Sydenham.

Sir Vincent is an 0-4-0WT compound loco with enclosed cab, steam brake and flywheel. Built in 1917 for Vickers Armstrong Ltd., armaments manufacturers of Erith, Kent, and named after her chief financier. Then in 1932 sold to British Oil and Cake Mills, also at Erith, Kent. Withdrawn in 1966 she was sold into preservation. Her then owner completely rebuilt her with a new firebox, coal bunker and tender, the work being completed in 1993. She arrived at Quainton in 1998, after previously visiting during 1994.

This locomotive form an interesting link with Quainton Road Station in that the Brill Tramway was worked by two Aveling & Porter locos between 1972 and 1894, one of which is normally in the London Transport Museum, Covent Garden London, and is currently on loan to Quainton.

Sir Vincent left Quainton in June 2003 for Daid Buck's private site at Fifield, Berkshire. In November 2025 the locomotive was put up for sale, amd is now believed to have moved by new owners to Scotland.

Current Location - Lanarkshire, Scotland (private site)

References:
Gallery of Locomotives previously located at Quainton - Quainton News No. 101 - April 2009