Thanks for the comments. My post only covered the highlights. As this sectional view of my 3D CAD model of the cylinder shows there are a lot of holes and other features that I didn't mention:
Many of the features are tapped holes and glands, as seen here:
I didn't use any old school marking out methods on the cylinder. Everything was machined using reference surfaces and edge finders, and the 2D DRO to locate and machine all the features. I expect that parts I make weeks, or months, apart will fit together without needing adjustment, as long as I follow my drawings. I can't claim a 100% record, but it's unusual for parts not to fit straight off the machine.
Andrew