I was poking around today and ran into this:
http://www.markinsamerica.com/MA5/TH.php?req=TH300
It seems to be a complete replacement for the Gitzo hub -- and it's solid aluminum.
It's not inexpensive, and I know you've ordered something from RRS, Phrasikleia, but if you don't get satisfaction from Gitzo you could get one of these and save the sticks.
The OP would still have to buy a new Gitzo to use that unless I'm mistaken. It mentions being fitted for a Series 3 Gitzo. She used a Series 2. A series 3 + that might be around the same cost as the RRS legset.