There has to be something wrong how George Pierce fits in here. At first I was very excited to find this post, but George is about the same age as his father Charles in this scenario. Yes, Charles Pierce and Phoebe are on George's marriage certificate listed above, but Charles would have to be the first man to conceive a child at age 2. I am excited that you found plausible links to your ancestor. George is my ancestor, and this Charles and Phoebe Pierce do not make sense for George and Grace. George and Grace also married around the same time as This Charles and Phoebe.
Thanks. Just wanted to point this out to any focused on George. Congrats again to your good finds.