I recently read one of few known source about Oliphants of Kellie
http://archive.org/details/eastneukoffifeit00wood/page/260/mode/2up
No Thomas nor Elisha don't mentioned in these source, as sons of these Sir Alexander..
Also there are doubts about Elisha name, because it's not Scottish name at all. It's more likely Puritan name, but not Scottish.
Please somebody, wrote the link to source, where Thomas and/or Elisha are mentioned as sons of these Alexander.