Hi No1_sonuk, in September 15, 2010, you said "Last night I discovered a flaw in my cunning plan...
Be careful if you try fly cutting up to a shoulder using an insert lathe tool. Depnding on the design of the tool, the support behind the insert might not have enough clearance to get round.
Mine didn't

"
The "cunning flawed plan" is still valid, and valid also is (my words) "The surface finish is rather scratchy, though. An HSS tool bit gives a better surface, but it must be really razor sharp.", meaning a round- tipped carbide tool, an exact copy of yours. (Glanze SRDCN 0808 D06).
"Scratchy" or "mirror finish" covers a lot of definitions, like a gently tap means someone's as an almighty devastating sledgehammer whack...

Excellent brass pyramids!