That's Anthony Mount's design for James Booth's Rectilinear Engine. Castings and drawings available from Polly/Bruce.
It was also covered in EiM many moons ago and was the first engine of many that Anthony has now done.
Can be built from scratch in which case a better buy than the drawing is his book "Historic Engines Worth Modelling " Vol 1 which ha sthe drawings and Text from the original EiM series
Edited By JasonB on 09/09/2023 13:11:59