Waverly Sayre and I think Donna Parker made one-off initial appearances in Green Lantern Corps Quarterly
back in the 1990s. Waverly supposedly became Green Lantern of Earth in the 19th century but his story was shrugged off as a "might-have-been". Donna lived in the 1950s or so and her story was presented as part of actual history because she declined
Both characters have been revisited more recently as far as I know.
Charley Vicker was a supporting GL character from way back, but I never quite figured out his story. He had his own ring, but I don't think he was ever the official Earth GL.