I found a description of an RFS roller from 1963, does this sound like it might be it?
“Seymours Castwell Foundry LTD., Raynesway, Spondon, Derby, produce this fully powered roller developed from the ‘Ogle’ hand roller. The cast iron double cylinder, 24-inch diameter by 24-inch wide, has well-rounded edges and front and rear scrapers are standard fittings.
Transmission from the 4-stroke Villiers engine is by Reynolds chain drive through an Albion gearbox giving a choice of three forward speeds and one reverse. Bottom forward speed is recommended for most operations and the two higher speeds for moving the roller from place to place. Top gear is useful when using the trailing seat over a large area.”
The RFS roller was advertised in three weights in 1963: light 6 cwt 3qrs at £159; medium 8cwt at £168, and heavy 9 cwt 2qrs at £177.
It appears Seymours Castwell, which was founded in 1947, made several manual pull-along cast iron rollers including the mentioned ‘Ogle’roller for gardens, golf courses etc. They were also a major casting company making items for many clients.