Andy, I quite agree with your reasoning re the hoses, etc….
Internet research reveals the following –
ILO engines/moteurs
Engine manufacturer ILO Motorenwerke was a major manufacturer of 2 stroke engines from 1911 until its decline in 1990’s. The company was founded by Heinrich Christiansen to produce 2 stroke engines at Altona, for many diverse uses. In 1923 to 1925 they also produced a range of motorcycles. In 1959 they where purchased by Rockwell international industries, who produced a range of snow mobiles, then later in 1977 they where acquired by machine giant Tecumseh. Under the Tecumseh brand they continued to expand production to supply engines for lawn mowers, compressors and agricultural items until the mid 1990’s. During there production history ILO produced, trains, all manor of engines but principally 2 stroke, (in fact in 1954 they where the largest producer of 2 stroke engines in West Germany with 184 000 units sold and over 1500 employees). Energic used ILO engines in many motoculteurs, motobinuses and motofaucheuse machines of there day. And to there credit, with the strength and quality of these engines, many Energic machines survive and are in daily use throughout France today.
The hydraulic hub mounted motors intrigued me, as clearly they were commercially manufactured; however no matter how hard I stared at them, I could not see any maker’s mark, etc…
Attached is a photograph of the engine maker’s plate, for info.
One line I have looked at using the Internet, is the fact that Coventry Climax, Massey Ferguson, and Warwick University (Motor Research Facility) are all within spitting distance of each other. Just a thought.