Thanks for the input. What a coincidence that today was the first chance I had to head to look at "American Nyes of English Origin". Turned out my local library has two copies! Through that I was able to confirm the Caroline/Ziba/Sylvanus line with quite a bit of detail I didn't know before. I also had access to the Howland books that show Sylvanus married one of the Howland descendants.

Now I am stuck with trying to verify that Caroline Nye was in fact married to my particular Ling branch. I'm told many of those records may have been lost in a fire.