George, I wish I had saved one of these just for a conversation piece. On a lot of 1930-1940 era services around here they grounded the meterbase and ran a piece of 1/2" rigid down to the ground to protect the bare #6. On the bottom end of the 1/2" rigid was a yoke that threaded on to the pipe and had a flat clamp with a 5/16" bolt through it to sandwich the GEC as it exited the pipe. Never have been able to take one apart. They were always grown into one piece from corrosion where they were in contact with the soil. I've pitched dozens. I think Blackburn still makes these.
I think the operative part of the question/answer is you can use the same hub to make a <pipe> electrode connection that you use to bond the far end of the GEC raceway. I am sure we have all seen those connectors.