The heavy chunks of brass which form the cylinders, and the intermediate cylinder valve chest, have been machined externally, and bolted together.
The IP valve case cavity has been machined, but 3mm too wide. I think that this error will not matter, but if it does I will silver solder some extra material to get to the specified dimension. (the external dimension of the steam chest is deliberately left too big at this stage. It will be blended with the cylinder blocks later.)
Now that these pieces are together, I can do the cylinder boring and complete the external dimensioning and finishing.