I have made engines and workshop tools from Hemmingway kits and always been happy with the kits. The quality of drawings and instruction sheets is very good, as are the materials supplied. In particular I have found the castings to be of very good quality; no holes or hard bits. As others have noted, the materials are often cut close to size, so some thought can be required on holding in the lathe or mill. Sometimes I substitute from my own stock if it is easier.
I am currently making the Fieldhouse engine (see photo) which is an interesting project. I live in France so probably won’t get to the Tolson Museum to see the original. However, the curator of the museum is very helpful and kindly sent me photos of it. It is worth bearing in mind that the flywheel is 8 5/16 “in diameter and the casting weighs 1.683Kg. The winding drum is also a bit of a lump, weighing in at 2.956 Kg. I have the equipment to cope with it, so no worries there. I have started to write a construction series for an article in Model Engineer but will not put much more effort into it until I see how the new style magazine develops.
I did have an article published in Model Engineer on the Ransome and May engine built from a Hemmingway kit in 2014. That was a nice engine to build and now powers my model of an engineering workshop.
Please don’t hesitate to ask if you have particular questions about constructing the Fieldhouse engine.