Interesting .Having been heavily involved in sleeving myself its interesting to see other peoples methods .
I see you cut off in front of the bars where others including myself cut off in front of the chamber cones .We didn't see you method of machining the backends and I would have liked to see how or if your way differed from ours , bearing in mind with welded joints the marrying up of faces would not be so critical as with soldered joints .Did surprise me that you bored chokes in the lathe before fitting the tubes though