Hi Brad,
A few years ago I built the modern Stuart Progress Engine for a friend and with it came a facsimile copy of the original construction booklet of 1913. The six engines described shared many components, so to make an engine you have to keep having to keep moving from page to page, which was a little confusing, so I made two photocopies of the booklet, cutting one up to just have all the information on the engine being built in one place. I checked my complete copy and what is referred to as the High Speed Horizontal Steam Engine or SH1 for short looks exactly like the model on eBay.
Take care Tony.