About 1964 International in the USA used Perkins an English diesel in their van trucks not sure of tonnage, the usual large mainly local delivery say 18 feet long. Driver said it got 19 miles per gallon, of course no smog concerns in those days. On a welding job used a welder with a Perkins diesel seemed to be an old unit. In Britain a company I worked for had a Reo Speed Wagon (chrome and all) when the engine needed replacing replaced with a Perkins. Believe Perkins was like Continental in the USA just built engines for others and or replacement. That Reo also included another name sure looked a twin to an International. Diesel engined trucks and busses popular in Britain in the 1930s.