Spit aerial mast length

Hi guys.
Our wood guy 😀 is doing up some of the more fun parts of the job by making up the non metalic parts of the Spit.We have found the remains of a couple of Spitfire aerial masts that were scrapped after the war and thrown into the fire.We are after the full length that goes down into the mast plate above the radio.I have been told the metal sheathing is copper is that correct?
Will get some pics up soon.:)