Wallacegeneologist on Family Tree Circles

I have been researching my family and cannot find a half brother. It is very strange almost like he did not exist. His name was David Hannan Wallace, Jr. I don't know when he was born but I know he married a lady named Linda Lou Marnie or Mayberry. I also know he was in the armed forces. I have not been able to find him even though I have found many more family members . If anyone can help I would appreciate it. His father was my father, David Hannan Wallace, Sr. and his mother was Margaret Viola Matthews. He grew up in West Virginia and then moved to Michigan, I think. Thank you.

I am having trouble following my line back past my paternal grandfather. His name was Charles A. Wallace, born March 1896. One record says his parents were born in Scotland and one record says his parents were born in West Virginia. He married Josephine May Martin and later married Mattie May Freeland. If you can help, I would be grateful. Thank you!