Doesn't the book contain drawings of all of the Allchin components? I've not seen it, but, as I remember, the two ME series describing the build, and which form the basis of the book. both show a full set of drawings together with very detailed advice on making and assembling the components. Admittedly, the full size drawings are nice to have but there's not a lot of change from £100 to buy them.
From what can be seen in the pictures, the OP seems to have a fairly complete basic engine, with the exception of the gear-change mechanism which seems to need some machining.