Thanks Guys
Much appreciate all Your kind comments
We used some scrap left-over material from shafting we had bought at the scrap Guys. Pretty sure the barrel-tube with the extension supports and the threaded knurled Lock-Rings are in BMS, (Bright Mild Steel), whilst the male threaded height-Setters are in Stainless Steel - also from Al-salvejo !!! ( Mr Salvage) These were from the place we used to work at and I am quite certain they were either 304 or 316 Stainless, 'cos that's what they had most their parts made in.
Yes, had a friend suggest we use fine Threads which suit the part perfectly.
Hope this helps answer the Q.
Adding our two-cents worth, and which might help others achieve similar if not better results, we may mention that all it would require are a few more extra minutes spent polishing on the Lathe that will enhance any part one makes; provided of course one keeps to the projected sizes and tolerances obviously.
Learnt this in the school of hard-knocks whilst polishing blades literally with blood sweat and tears. Man, would U need elbow grease there !!!
aRM