I've not seen it modeled before so looks like its a case of getting some good square on photos, picking the size of flywheel you can manage and them proportioning everything else from that. It does not look too had a one to fabricate, you could always use something like the Vulcan beam as a basis to get the main working sizes and then detail it to represent this engine, the compound cylinders would make it an interesting subject.
Preston's also have a Woolf compound beam engine so you may be able to get some details from that too, they steam it on their open days, I took these at the last one.



J
Edited By JasonB on 05/06/2014 17:22:30
Edited By JasonB on 05/06/2014 17:26:30