I managed to get some black aluminium turnbuckles for the Mi5Evo! The ones for the ARC R10 are 37mm and fit for suspension and steering (search for ARC R102815). About 7g in weight savings for 6 turnbuckles. I'm still searching for a longer one to replace the servo turnbuckle, but until now had no luck.
Anyone knows where I can get a aluminium turnbuckle in 52mm?
Another question: has anybody used the aluminium chassis from Avid? How does it compare to the original one from Schumacher?