OK, I'm trying to nail down which William Brunner (either of them) you are related to. This is what I have so far. Your GGG Grandfather was William Brunner, his son, also a William, married Rebecca Custer. Rebecca's mother was Ada Van Fossen (Fosson?) Without any dates it is difficult to figure out. I'm thinking the Rebecca I found on LDS is probably the one making the birthdates of her and William sometime in the mid 1800s.