Mark: there is thin, pure, solid-copper sheeting available from art supply stores which would be very easily formed around a wooden core or "mold". 

You might consider trying that yourself, if you cannot find anyone who does that commercially.

 

The stuff is a little thicker than aluminum foil, yet strong enough to hold together well even after being worked.  

I would wrap it around the core, solder it up the "back-side"  and form it around the top with a small hammer, if necessary, then connect it to the cable at the bottom.

Ken W7EKB