RE: dual elevator pushrod setup
David,
I've used Dave Brown fiberglass pushrods that have a Y connection in them on every pattern ship I've built. As long as you mount your elevator servo where it has an absolutely straight run to the Y both elevator halves will move equally. It may take a bit of time to properly bend and align the Y.... but it is just a method I've always used and still use today.
Dan
Carolina Custom Aircraft