previous Tickford model, being built with simple metal panels and bolt-together construction instead of the complex wooden structure of the older Station Wagon. They were intended to be used both as commercial vehicles as people-carriers for transporting workmen to remote locations, as well as by private users. Like the Tickford version, they came with basic interior trim and equipment such as roof vents and interior lights. The Station Wagons saw the first expansion of the Land Rover range. Station Wagons were fitted with a "Tropical Roof" which consisted of a second roof skin fitted on top of the vehicle. This kept the interior cool in hot weather and reduced condensation in cold weather. Vents fitted in the roof allowed added ventilation to the interior. While they were based on the same chassis and drivetrains as the standard vehicles, Station Wagons carried different chassis numbers, special badging, and were advertised in separate brochures. Unlike the original Station Wagon, the new in-house versions were highly popular. In mid-1956 the wheelbases were extended by to and , and the front chassis cross-member was moved an inch forward, to accommodate the new diesel engine, to be an option the following year. This change was made to all models with the exception of the 107 Station Wagon, which would never be fitted with a diesel engine, and would eventually be the last series I in production. These dimensions were to be used on all Land Rovers for the next 25 years. In 1957 a brand new 2.0-litre diesel engine was introduced that, despite the similar capacity, was not related to the petrol engines used. The petrol engines of the time used the rather out-dated inlet-over-exhaust valve arrangement; the diesel used the more modern overhead valve layout. This diesel engine was one of the first high-speed diesels developed for road use, producing at 4,000 rpm. Series II The successor to the successful series I was the series II, which saw a production run from 1958 to 1961. It came in and wheelbases (normally referred to as the 'SWB' and 'LWB'). This was the first Land Rover to receive the attention of Rover's styling department. Chief Stylist David Bache produced the familiar 'barrel side' waistline, with a greater width to cover the vehicle's wider tracks, as well as the improved design of the truck cab variant, introducing the curved side windows and rounded roof still used on