Alone Together cover/title page illustration idea
The very early versions of the story (30 or more years ago) had a very different airplane design and different character designs, the girl was originally based on a Jerry Collins style creature, but that didn't go very far as he was not interested in a collaboration, and a human guy. This version is obviously based on the setting as now told.
End notes two
Erma Felna of the EDF
Alone together shadow fish 2