In 1966-7 a small construction machinery company designed and built these 4wd tractors based on the Ford 5000 tractors. The front axle was reversed 5000 axle. They were underpowered and a few 6 cylinder versions were made. Sales were poor and the parent company went bust.
The designer David Brown [no relation to David Brown tractors] joined Muir Hill another construction machinery manufacturer, took his ideas and Muir Hill went on to produce a highly successful range of 4wd tractors which had the same basic ideas as the Northrop.
Although Muir Hill ceased building tractors in the 1990's, a company who took over the spares business still build these tractors to order for farming and for off road haulage of goose neck dump trailers.