Colonel Stephens made use of a wide variety of different vehicles on his light railways. The adjacent picture shows a model of a Ford Railmotor under construction, complete except for the painting and comes from the steamandthings website. 
Colonel Stephens purchased four pairs of these Railmotors. The earliest set was purchased for the Kent & East Sussex Railway (K&ESR).
Stephens built his first independent railway, the Rye and Camber, intending to use ‘an oil motor on a bogie passenger car’ to operate the service. This was a step too far. The internal combustion engine was less than ten years old and Stephens was unable to realise his ambition. A small steam locomotive had to be used. 
Ten years later he returned with another innovation, a light steam railmotor. It proved mechanically unreliable and inevitably the First World War brought the experiment to an end. During the First World War petrol road lorry and bus development leapt forward and traffic on rural railways was under threat. To help counter this, Stephens returned to the new technology. A first experiment was in October 1921 on the Weston, Clevedon and Portishead but the vehicles were effectively hand built one-off products and therefore expensive; too expensive to adopt on cash starved independent light railways. 
The Colonel Stephens Society continues: “Stephens had begun experimenting on the Kent & East Sussex at some time before 1921 with a cheaper alternative using an Edwardian Wolseley-Siddeley car chassis that was adapted as a rail lorry and then as a bus. In using such adaptations Stephens was in the forefront of world practice, for only a few lines in North America and one French manufacturer were trying such things at the time.”  Details of this vehicle can be found at: https://rogerfarnworth.com/2019/07/27/gazelles-trailers. Its ultimate use was as a reconstructed coach to run behind the locomotive Gazelle on the Shropshire & Montgomery Light Railway. 
Ford Railmotor set No. 1 arrived on the Kent and East Sussex in 1922, featuring in the Commercial Motor Magazine of 12th December 1922.  It came from Edmonds of Thetford. The bodywork was made by Eton Coachworks of Cringleford. The seating capacity was 20 in each car. Later models had the same capacity in seating but some design differences. Set No. 1 can be seen in the picture below.
Railmotor No. 1 on the K&ESR at Tenterden in 1923, sitting alongside an Ilfracombe goods loco (c) Colonel Stephens Museum. In its early years the railmotor sets had head lamps either side of the radiator. Later a headlamp was sited on the roof 
Ford Railmotor No. 1 at Tenterden Town Station, (c) Ronald Shephard Collection, West Sussex Record Office Ref No: Shephard 1/28/1. 
The twin T type Ford set at Headcorn Junction, (c) Ronald Shephard Collection, West Sussex Record Office Ref No: Shephard 1/28/5. 
Ford Railcar at Tenterden Town Station on the Kent and East Sussex Railway. The line opened in 1900 as the Rother Valley Railway from Robertsbridge to Tenterden Town in 1903 and to headcorn in May 1905. In 1904 the name of the line was changed to the Kent & East Sussex Railway, (c) Ronald Shephard Collection, West Sussex Record Office Ref No: Shephard 1/28/3. 
In September 1923, Stephens wrote to the Commercial Motor Magazine saying: “I have nine small steam railways under my control and am trying several forms of motor trains…. In a previous experiment I learnt, to my sorrow, that it is cheaper to have a car at each end than to put in a reverse gear.’ Col. Stephens gave his reason for choosing Ford chassis as follows: ‘The motive units are the much despised 1-ton Fords; we chose this type, as we can always get spares without delay and for no other reason.” 
There were problems with reliability but these railmotors provided a much more efficient passenger service than did the mixed trains that preceded them. One significant advantage for passengers was that they were not detained at intermediate stops to shunt goods wagons. Set No. 1 was followed 12 months or so later by set No. 2 of a very similar design. The second set had all the strengths and weaknesses of the first set but could easily be distinguished from set No. 1 as its windscreen was divided into three panes of glass rather than into two.
Ford Railmotor No. 2 on the K&ESR at Rolvenden in the 1930s. 
Ford Railmotor No. 2 on the K&ESR at Junction Road in 1930. 
The third Ford Railmotor set was also supplied by Edmonds of Thetford and was very similar to Ford Railmotor No. 2. It ran on the Selsey Tramway. It arrived with headlamps either side of the radiator in 1924 as shown in the adjacent image. 
The next image is a CAD image from Shapeways showing their 3-print of the second design of Ford Railmotor. 
The fourth of the Ford Railmotor sets purchased by Colonel Stephens was for the Shropshire & Montgomery. It was purchased in 1923 and perhaps should be referred to as the second set. As it set the design parameters for the remaining Ford Railmotor sets bought by Colonel Stephens. This fourth set was different from the other paired sets in that it was provided with a central carriage, increasing the passenger carrying capacity. Visually, the two powered cars were identical to sets 2 and 3 above. Sadly, it may be that these Railmotors were under-powered and the use of the central carriage on the incline out of Shrewsbury Abbey Station may have been impracticable with the intended passenger loading. [1: p22]
The Shropshire & Montgomeryshire Light Railway Ford Railmotor set. 
Interestingly, these Railmotors kept the low level headlights, or at least one of them throughout their lives. It was usual to see the powered cars working together and the central carriage laid up in a siding somewhere! In most cases pictures show only the two paired powered cars. The usually operated along the S&MLR mainline and left the brach to Gazelle and is coaches.
The Ford Railmotor set in action at Kennerley in 1926. Note the missing headlamp. 
The adjacent image shows Criggion station and is dated 5th August 1935. The Ford Railmotor has made an unusual excursion up the branch line. It is on a showing a Railcar set at the platform on a summer excursion from Kinnerley, (c) Roger Carpenter. 
- Stephen Garrett & John Scott-Morgan; Colonel Stephens Railmotors; Irwell Press, Caernarfon, 1995.
- http://www.steamandthings.com/page44a.htm, accessed on 27th July 2019.
- https://twitter.com/KandESRailway/status/923509399003549698?s=19, accessed on 27th July 2019.
- http://colonelstephenssociety.co.uk/rollingstock%20topics/ford%20railmotors.html, accessed on 27th July 2019.
- https://www.sussexpictures.co.uk/west-sussex-record-office/ronald-shephard-railway, accessed on 27th July 2019.
- http://railwayheritageroutes.blogspot.com/2017/02/the-ford-railcar-at-rolvenden.html, accessed on 27th July 2019.
- http://colonelstephenssociety.co.uk/kent%20and%20east%20sussex/accident%20at%20junction%20rd.html, accessed on 28th July 2019.
- http://www.steamandthings.com/page44.htm, accessed on 28th July 2019.
- https://www.shapeways.com/product/38RB92Y8V/0-55-ford-railcar-1a, accessed on 28th July 2019.
- http://colonelstephenssociety.co.uk/colonel%20stephens%2C%20kits%20and%20models/ford%20railmotor.html, accessed on 28th July 2019.
- John Scott-Morgan; British Independent Light Railways; David & Charles, Newton Abbott, Devon, 1980; p84.
- http://www.oswestry-borderland-heritage.co.uk/?page=115, accessed on 14th May 2019